Pressure sensor with improved suppression of undesired stimuli

Abstract

The invention relates to a pressure sensor with improved suppression of undesired stimuli. The pressure sensor is provided with: a body having a first chamber and a second chamber, the second chamber being hermetically separated from the first chamber; and a first detection structure disposed in the first chamber, having a first deformable element and a first buried cavity within the first detection structure, the first deformable element configured to undergo deformation in accordance with a pressure difference between the first chamber and the first buried cavity. The sensor also has a second detection structure disposed in the second chamber having a second deformable element and a second buried cavity within the second detection structure, the second deformable element configured to undergo deformation as a function of a pressure difference between the second chamber and the second buried cavity. The sensor also has a first channel extending into the body and configured to fluidly couple the first buried cavity with the second chamber; and a second channel extending into the body and configured to fluidly couple the second buried cavity to the first chamber.

Description

Technical Field

[0001] The present disclosure relates to pressure sensors, in particular to pressure sensors of the MEMS ("Micro Electro Mechanical Systems") type having improved suppression of undesired stimuli. Background Art

[0002] Known MEMS pressure sensors have a membrane configured to deform according to the external pressure to be measured. By detecting the deformation of the membrane, for example by means of a piezoresistors, a measurement of the external pressure can be obtained.

[0003] However, as is known, MEMS pressure sensors are subject to undesired mechanical stimulation, which may cause spurious, undesired deformation of the membrane. This results in low detection accuracy of the MEMS pressure sensor.

[0004] Undesirable mechanical stimuli can be divided into: external stimuli, such as bending of the PCB on which the pressure sensor is mounted, thermal expansion of the pressure sensor package, humidity, etc.; and internal stimuli, such as thermal expansion of the material forming the pressure sensor and hysteresis of residual mechanical stress following temperature changes.

[0005] According to one approach, the membrane is formed as a structure suspended relative to the body of the pressure sensor. This allows the membrane to be decoupled from external mechanical stimuli. However, in this approach, the membrane is still sensitive to internal mechanical stimuli.

[0006] According to a different approach, the MEMS pressure sensor includes another membrane that is configured not to deform according to the external pressure. This other membrane can be used as a reference to offset the deformation contribution caused by the internal mechanical stimulus. However, the fact that this other membrane does not deform according to the pressure to be measured makes the pressure sensor have low sensitivity and high area occupation. Summary of the invention

[0007] According to the present disclosure, a pressure sensor is thus provided. The pressure sensor has: a body having a first chamber and a second chamber, the second chamber being hermetically separated from the first chamber; a first detection structure arranged in the first chamber, having a first deformable element and a first buried cavity within the first detection structure, wherein the first deformable element is configured to undergo deformation according to a pressure difference between the first chamber and the first buried cavity. The sensor also has a second detection structure, the second detection structure being arranged in the second chamber, having a second deformable element and a second buried cavity within the second detection structure, wherein the second deformable element is configured to undergo deformation according to a pressure difference between the second chamber and the second buried cavity. The sensor also has: a first channel extending into the body and configured to fluidically couple the first buried cavity with the second chamber; and a second channel extending into the body and configured to fluidically couple the second buried cavity to the first chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] For a better understanding of the present disclosure, embodiments of the present disclosure will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:

[0009] Figure 1 shows a top plan view of a MEMS pressure sensor according to one embodiment;

[0010] Figure 2 Shown along Figure 1 Section line II-II Figure 1 A cross-sectional view of a MEMS pressure sensor;

[0011] Figure 3 Shown along Figure 1 Section line III-III Figure 1 A cross-sectional view of a portion of a MEMS pressure sensor;

[0012] Figure 4 Shown along Figure 1 Section line IV-IV Figure 1 A cross-sectional view of different parts of a MEMS pressure sensor;

[0013] Figure 5 Shown with Figure 1 A circuit diagram of a detection circuit that can be coupled to a MEMS pressure sensor;

[0014] Figure 6 Shown in use Figure 1 A simplified view of a portion of a MEMS pressure sensor;

[0015] Figure 7 shows a cross-sectional view of a MEMS pressure sensor according to various embodiments; and

[0016] Figure 8 A circuit diagram of a detection circuit that may be coupled to a MEMS pressure sensor is shown according to one embodiment. DETAILED DESCRIPTION

[0017] The following description refers to the arrangements shown in the accompanying drawings; therefore, expressions (such as "above", "below", "lower", "upper", "right", "left", "top", "bottom", etc.) are related to the drawings and should not be interpreted in a limiting manner.

[0018] Figure 1 and Figure 2 The pressure sensor 1 is shown in a Cartesian reference system XYZ having a first axis X, a second axis Y and a third axis Z, the pressure sensor 1 being also referred to hereinafter as sensor 1 for short.

[0019] The sensor 1 is of MEMS type.

[0020] The sensor 1 can be manufactured by micro- and nano-fabrication techniques known per se, e.g. starting from a wafer of semiconductor material, in particular silicon, and subsequent processing steps, e.g. comprising photolithography, chemical etching, growth, annealing, slicing, bonding, etc. typical of the semiconductor industry.

[0021] The sensor 1 is configured to detect the external pressure P ext .

[0022] The sensor 1 is formed in a body 5 comprising a lower substrate 7 and an upper substrate 9 bonded to each other via a bonding area 10 .

[0023] The lower substrate 7 and the upper substrate 9 have a semiconductor material, in particular silicon. However, depending on the specific manufacturing process used, the lower substrate 7 and the upper substrate 9 may be composed of different materials or include a portion or layer of different materials (eg, insulating materials).

[0024] The bonding region 10 has a material that allows a hermetic bond to be obtained between the lower substrate 7 and the upper substrate 9. For example, the bonding region 10 may have aluminum-germanium (Al-Ge). Bonding by Al-Ge may allow very low pressures to be obtained, for example, even below 20 mbar.

[0025] For the sake of clarity, Figure 1 The sensor 1 is shown without the upper substrate 9 .

[0026] The sensor 1 includes a first chamber 12 and a second chamber 13 arranged in a body 5. The first chamber 12 and the second chamber 13 extend into a first surface 14 of a lower substrate 7 of the body 5 and terminate within the lower substrate 7 of the body 5 before reaching a second surface 16 of the lower substrate 7 of the body 5 opposite to the first surface 14. A wall 17 of the lower substrate 7 of the body is between the first chamber 12 and the second chamber 13, and the wall 17 partially defines the first chamber 12 and partially defines the second chamber 13.

[0027] The first chamber 12 and the second chamber 13 can be separated from each other in a gas-tight manner by the bonding area 10 .

[0028] In this embodiment, the body 5 comprises an opening 15 coupling the first chamber 12 with the outside of the sensor 1. In other words, the opening 15 places the first chamber 12 at the external pressure P ext .

[0029] In the embodiment shown, the opening 15 extends along the third axis Z through the upper substrate 9 over its entire thickness.

[0030] The sensor 1 further comprises a first detection structure 18 arranged in the first chamber 12 and a second detection structure 19 arranged in the second chamber 13 .

[0031] In detail, in this embodiment, the first detection structure 18 and the second detection structure 19 are structures suspended in the first chamber 12 and the second chamber 13 respectively by corresponding elastic elements 21 and 22 .

[0032] The first and second detection structures 18 and 19 as well as the elastic elements 21 , 22 may be composed of semiconductor material, in particular silicon, starting from the same wafer used to form the lower substrate 7 , by subsequent processing steps including photolithography, growth, chemical etching and the like.

[0033] The elastic element 21 extends into the first chamber 12, between the first detection structure 18 and the lower substrate 7. The elastic element 22 extends into the second chamber 13, between the second detection structure 19 and the lower substrate 7.

[0034] The elastic elements 21, 22 are configured to mechanically decouple each of the respective detection structures 18, 19 from the lower substrate 7. In this way, the detection structures 18, 19 can be decoupled by an external mechanical stimulus applied to the body 5.

[0035] During the design step, the shape and size of the elastic elements 21 , 22 may be selected based on the desired elastic properties of the elastic elements 21 , 22 .

[0036] The first detection structure 18 includes a buried cavity 24 extending within the first detection structure 18 and a membrane 25 facing the buried cavity 24 .

[0037] In detail, the film 25 has a lower surface 25A facing the buried cavity 24 and an upper surface 25B facing the first chamber 12 .

[0038] In practice, the buried cavity 24 delimits the bottom of the membrane 25 and the first chamber 12 delimits the top of the membrane 25 .

[0039] During the design step, the location of the buried cavity 24 within the first detection structure 18 and the dimensions of the buried cavity 24 may be selected according to the desired dimensions of the membrane 25. For example, the membrane 25 may have a thickness along the third axis Z (for example comprised between 2 μm and 20 μm) and an area measured in the XY plane (40×40 μm comprised). 2 and 600×600μm 2 between).

[0040] The second detection structure 19 includes a buried cavity 30 extending within the second detection structure 19 and a membrane 32 facing the buried cavity 30 .

[0041] In detail, the film 32 has a lower surface 32A facing the buried cavity 30 and an upper surface 32B facing the second chamber 13 .

[0042] In practice, buried cavity 30 delimits the bottom of membrane 32 and second chamber 13 delimits the top of membrane 32 .

[0043] During the design step, the location of the buried cavity 30 within the second detection structure 19 and the dimensions of the buried cavity 30 may be selected according to the desired dimensions of the membrane 32. For example, the membrane 32 may have a thickness along the third axis Z (for example comprised between 2 μm and 20 μm) and an area measured in the XY plane (40×40 μm comprised). 2 and 600×600μm 2 between).

[0044] In particular, the first detection structure 18 and the second detection structure 19 can be designed identically to each other. For example, the membranes 30, 32 can have identical dimensions to each other. This allows the detection accuracy of the sensor 1 to be improved.

[0045] The sensor 1 further comprises a channel 40 and a channel 41 , the channel 40 extending into the body 5 between the buried cavity 24 and the second chamber 13 , and the channel 41 extending into the body 5 between the buried cavity 30 and the first chamber 12 .

[0046] Channel 40 (details of which are in Figure 3 and Figure 4 ) opens at a first end on the buried cavity 24 and at a second end on the second chamber 13.

[0047] In practice, the channel 40 places the buried cavity 24 and the second chamber 13 at the same pressure P1.

[0048] The channel 41 opens at a first end on the buried cavity 30 and at a second end on the first chamber 12 .

[0049] In fact, the channel 41 makes the buried cavity 30 and the first chamber 12 at the same pressure P2, which is equal to the external pressure P ext .

[0050] In detail, the channel 40 starts from the buried cavity 24 , is buried in the first detection structure 18 , the elastic element 21 and a portion of the lower substrate 7 , and extends toward the second chamber 13 .

[0051] In this embodiment, the channel 40 comprises a via 43 extending from the surface of the lower substrate 7 facing the second chamber 13 towards the interior of the lower substrate 7 along the third axis Z. In fact, the via 43 may fluidically couple the buried portion of the channel 40 with the second chamber 13 .

[0052] In detail, the channel 41 starts from the buried cavity 30 , is buried in the second detection structure 19 , the elastic element 22 and a portion of the lower substrate 7 , and extends toward the first chamber 12 .

[0053] In this embodiment, the channel 41 comprises a via 44 extending from the surface of the lower substrate 7 facing the first chamber 12 towards the interior of the lower substrate 7 along the third axis Z. In practice, the via 44 may fluidically couple the buried portion of the channel 41 with the first chamber 12 .

[0054] The buried cavities 24, 30 and buried portions of the channels 40, 41 may be formed, for example, by forming and subsequently removing a sacrificial layer; or by subsequent steps including growth, photolithography, chemical etching and annealing, as described, for example, in European patent EP1577656.

[0055] The vias 43 , 44 may be formed with the same chemical etching used to define the resilient elements 21 , 22 and the detection structures 18 , 19 .

[0056] The sensor 1 further comprises one or more transducing elements (here, two piezoresistors 46 , 47 ) coupled to the first detection structure 18 and one or more transducing elements (here, two piezoresistors 48 , 49 ) coupled to the second detection structure 19 .

[0057] The piezoresistors 46 , 47 are configured to detect deformation of the membrane 25 .

[0058] Specifically, the piezoresistors 46 and 47 have resistances R1 and R3 , respectively, and the resistances R1 and R3 are variable according to the deformation of the film 25 .

[0059] In particular, the resistances R1 , R3 are sensitive both to the direction (upwards or downwards along the third axis Z) and to the degree of deformation of the membrane 25 .

[0060] In this embodiment, the piezoresistors 46 , 47 are configured such that the respective resistances R1 , R3 undergo changes of opposite sign to one another in response to deformation of the membrane 25 .

[0061] For example, in response to membrane 25 deforming downwardly, piezoresistors 47 may be configured to experience a positive change (increase) in corresponding resistance R3 , and piezoresistors 46 may be configured to experience a negative change (decrease) in corresponding resistance R1 .

[0062] The piezoresistors 48 , 49 are configured to detect deformations of the membrane 32 .

[0063] Specifically, the piezoresistors 48 and 49 have resistances R2 and R4 , respectively, and the resistances R2 and R4 are variable according to the deformation of the film 32 .

[0064] In particular, the resistances R2 , R4 are sensitive both to the direction (upwards or downwards along the third axis Z) and to the degree of deformation of the membrane 32 .

[0065] In this embodiment, the piezoresistors 48, 49 are configured so that the respective resistances R2, R4 undergo changes of opposite sign to one another in response to deformation of the membrane 32. For example, in response to the membrane 32 deforming upward, the piezoresistors 48 may be configured to undergo a positive change (increase) in the respective resistance R2, and the piezoresistors 49 may be configured to undergo a negative change (decrease) in the respective resistance R4.

[0066] The sensor 1 also comprises electrical connection means, including contact pads 50 and metal connection tracks (not shown here), which allow the sensor 1 (in particular the transducing elements 46 to 49 ) to be electrically connected to an electrical detection circuit for reading the resistors R1 to R4 .

[0067] Figure 5 An embodiment of a detection circuit, indicated here by 50, is shown, in which the piezoresistors 46 to 49 are connected at a supply voltage V cc and ground GND are electrically coupled to each other in a Wheatstone bridge configuration.

[0068] Specifically, the piezoresistors 46 and 47 form a half bridge and are connected in series at the power supply voltage V cc The piezoresistors 48 and 49 form a half bridge and are connected in series at the power supply voltage V cc and ground GND.

[0069] An operational amplifier 52 is coupled to the piezoresistors 46 to 49 and provides a voltage Vout.

[0070] In use, in the presence of an external pressure P to be measured ext In this case, the pressure P2 of the first chamber 12 and the buried cavity 30 is equal to the external pressure P ext .

[0071] Therefore, there is a pressure difference P between the upper surface 25B and the lower surface 25A of the membrane 25. ext -P1, and there is a pressure difference P1-P between the upper surface 32B and the lower surface 32A of the membrane 32 ext .

[0072] In practice, the membranes 25, 32 are subjected, in use, to pressure differences of equal magnitude but opposite sign.

[0073] Figure 6 It shows that P ext = Example of P2 > P1 In this case, the membrane 25 undergoes a downward deformation, while the membrane 32 undergoes an upward deformation.

[0074] The Wheatstone bridge configuration of the transducer elements 46 to 49 allows the pressure P to be obtained. ext Differential detection; therefore, any parasitic mechanical stress that may affect the first detection structure 18 and the second detection structure 19 can be eliminated as a common mode. Therefore, the sensor 1 can also have a high suppression of internal undesired mechanical stimuli. In addition, both membranes 25 and 32 are responsive to the external pressure P ext deformation; therefore, both membranes 25, 32 contribute to allow measurement of the external pressure P ext Therefore, the sensor 1 can have a high detection sensitivity.

[0075] Figure 7 A schematic cross-sectional view of a MEMS pressure sensor 100 according to various embodiments is shown. The sensor 100 has a similar overall structure to that of the sensor 1; therefore, like elements are indicated by like reference numerals and are not described in further detail.

[0076] The sensor 100 comprises a body 5 having a lower substrate 7 and an upper substrate, here indicated by 109 , which are bonded to each other via a bonding area 10 .

[0077] The sensor 100 has a first chamber 12 and a second chamber 13 , in which a first detection structure 18 and a second detection structure 19 are respectively accommodated.

[0078] In addition, in this embodiment, the first detection structure 18 is a structure suspended by the elastic element 21 and includes a buried cavity 24 and a membrane 25 ; and the second detection structure 19 is a structure suspended by the elastic element 22 and includes a buried cavity 30 and a membrane 32 .

[0079] In addition, here, the first chamber 12 and the buried cavity 30 are fluidly coupled by a channel 40 , and the second chamber 13 and the buried cavity 24 are fluidly coupled by a channel 41 .

[0080] In this embodiment, the opening 15 is a first opening of the upper substrate 109 , and the upper substrate 109 further includes a second opening 115 on the second chamber 13 .

[0081] Although not shown, similarly to what has been discussed for the sensor 1 , transducing elements are coupled to the membranes 25 , 32 to detect respective deformations.

[0082] In fact, in this embodiment, the sensor 100 can be used as two external pressure P ext , P ext ′Pressure difference sensor between.

[0083] In fact, here, the first chamber 12 and the buried cavity 30 are at a pressure P ext, and the second chamber 13 and the buried cavity 24 are at a pressure P ext ′.

[0084] Finally, it is clear that modifications and variations may be made to the sensor 1 , 100 described and illustrated herein without departing from the scope of the present disclosure, hereby defined in the appended claims.

[0085] For example, (one or both) the openings 15 , 115 may be formed through the lower substrate 7 but not through the upper substrate 9 , 109 .

[0086] For example, depending on the specific application, the detection structures 18 , 19 , the membranes 25 , 32 and the elastic elements 21 , 22 may have shapes different from those shown.

[0087] The membranes 25, 32 may have a non-square shape in plane, for example, rectangular or other type (eg, regular or irregular, such as polygonal with different numbers of sides), or they may have a substantially circular shape.

[0088] For example, the membrane 25, 32 may be a deformable element (eg, cantilever or otherwise) configured to deform in response to a pressure differential, the deformable element being of a different type and shape than the membrane.

[0089] For example, the detection structures 18 , 19 may be structures that are not suspended and are integral with the body 5 , in particular, the lower substrate 7 .

[0090] For example, the pressure sensor may include one or more getter layers disposed on one or more walls of one or more of the chambers 12, 13 and the buried cavities 25, 32. In particular, referring to Figure 1 In the described absolute pressure sensor, the getter layer may be arranged on the (lower) inner wall of the upper substrate 9 facing the second chamber 13 in order to make the pressure P1 as low as possible.

[0091] For example, the transducer elements 46 to 49 may be based on different transducer principles (eg piezoelectric, capacitive, etc.) to detect deformations of the membranes 25 , 32 .

[0092] The present pressure sensor may have a different number of transducer elements (eg, one for each of the membranes 25, 32), and / or the transducer elements may be coupled to each other depending on the circuit configuration.

[0093] For example, Figure 8 Different embodiments of a detection circuit, indicated here by 150 , are shown, which can be used in the case where the present sensor has only one transducing element 152 coupled to the membrane 25 and only one transducing element 153 coupled to the membrane 32 .

[0094] The transducing elements 152 , 153 are piezoresistors having resistances R1 and R2 , respectively.

[0095] The piezoresistors 152, 153 are sensitive to the deformation of the respective membrane 25, 32 in the direction along the third axis Z. In particular, the piezoresistors 152, 153 are configured such that the respective resistances R1, R2 undergo a positive (or alternatively, negative) change in response to the respective membrane 25, 32 deforming upward, and undergo a negative (or alternatively, positive) change in response to the respective membrane 25, 32 deforming downward.

[0096] The detection circuit 150 is an Anderson loop in which piezoresistors 152 , 153 are arranged in series with each other.

[0097] In detail, the detection circuit 150 includes: a current generator 155, which provides a reading current to the piezoresistors 152, 153; an operational amplifier 156, which is coupled to the piezoresistors 152 at an input; an operational amplifier 157, which is coupled to the piezoresistors 153 at an input; and an operational amplifier 158, which is coupled to the outputs of the operational amplifiers 156, 157 and provides a voltage Vout. In fact, the operational amplifier 158 operates as a subtractor, which cancels any common mode stress components that affect the changes in the resistances R1, R2.

[0098] In this way, the output voltage Vout varies only as a function of the external pressure to be measured and, at least as a first approximation, is independent of parasitic mechanical stresses.

[0099] Depending on the specific application, the electrical detection circuit 50, 150 may be integrated in the same die in which the sensor is integrated, or in a separate die.

[0100] The electrical connections between the transducing elements may be formed in the die in which the transducing elements are formed, or in the die in which the detection circuitry is formed.

[0101] Finally, the different embodiments described above may be combined to provide other solutions.

[0102] A pressure sensor (1; 100) is summarized as comprising: a body (5) having a first chamber (12) and a second chamber (13), the second chamber being hermetically separated from the first chamber; a first detection structure (18) arranged in the first chamber (12), comprising a first deformable element (25) and a first buried cavity (24) within the first detection structure, wherein the first deformable element is configured to undergo deformation according to a pressure difference between the first chamber and the first buried cavity; a second detection structure (19) arranged in the second chamber (13) The invention relates to a method for detecting a second deformable element in a second detection structure, comprising a second deformable element (32) and a second buried cavity (30) within a second detection structure, wherein the second deformable element is configured to undergo deformation according to a pressure difference between the second chamber and the second buried cavity; a first channel (40, 43) extending into the body (5) and configured to fluidically couple the first buried cavity (24) with the second chamber (13); and a second channel (41, 44) extending into the body (5) and configured to fluidically couple the second buried cavity (30) with the first chamber (12).

[0103] The first deformable element (25) has a first surface (25A) facing the first buried cavity (24) and a second surface (25B) opposite to the first surface and facing the first chamber (12), and the second deformable element (32) has a first surface (32A) facing the second buried cavity (30) and a second surface (32B) opposite to the first surface and facing the second chamber (13).

[0104] The first detection structure (18) is a structure suspended in the first chamber (12) and / or the second detection structure (19) is a structure suspended in the second chamber (13).

[0105] The pressure sensor may include at least one opening (15; 115) extending through the body (5) and configured to connect one of the first chamber and the second chamber to an external pressure (P ext , P ext ')coupling.

[0106] The at least one opening is a first opening (15) configured to connect the first chamber (12) to an external pressure (P ext ) fluid coupling, the sensor further comprising a second opening (115) extending through the body (5) and configured to connect the second chamber (13) to a second external pressure (P ext ') Fluid coupling.

[0107] The body (5) comprises a lower substrate (7), an upper substrate (9; 109) and a bonding region (10), wherein the bonding region is configured to hermetically bond the upper substrate to the lower substrate.

[0108] The pressure sensor also includes at least one first transducer element (46, 47; 152) and at least one second transducer element (48, 49; 153), wherein the at least one first transducer element is configured to detect the deformation of the first deformable element (25), and the at least one second transducer element is configured to detect the deformation of the second deformable element (32).

[0109] The at least one first transducer element (46, 47; 152) is sensitive to the deformation direction of the first deformable element (25), and the at least one second transducer element (48, 49; 153) is sensitive to the deformation direction of the second deformable element (32).

[0110] The at least one first transducer element and / or the at least one second transducer element is a piezoresistor.

[0111] The pressure sensor also includes a detection circuit (50; 150) configured to perform a differential reading of the deformation of the first deformable element (25) and the second deformable element (32).

[0112] Pressure sensors are of the MEMS type.

[0113] The various embodiments described above can be combined to provide other embodiments. Aspects of the embodiments can be modified, if necessary, to employ the concepts of the various patents, applications, and publications to provide other embodiments.

[0114] These and other changes can be made to the embodiments in light of the above detailed description. In general, in the following claims, the terms used should not be understood to limit the claims to the specific embodiments disclosed in the specification and claims, but should be understood to include all possible embodiments within the entire equivalent scope of the rights granted to such claims. Accordingly, the claims are not limited by the present disclosure.

Claims

1. A pressure sensor, comprising: A body, the body having a first chamber and a second chamber, the second chamber being hermetically separated from the first chamber; a first detection structure disposed in the first chamber, the first detection structure comprising a first deformable element and a first buried cavity within the first detection structure, wherein the first deformable element is configured to undergo deformation in operation according to a pressure difference between the first chamber and the first buried cavity; a second detection structure disposed in the second chamber, the second detection structure comprising a second deformable element and a second buried cavity within the second detection structure, wherein the second deformable element is configured to undergo deformation in operation in accordance with a pressure difference between the second chamber and the second buried cavity; a first channel extending into the body, the first channel fluidly coupling the first buried cavity with the second chamber; as well as A second channel extends into the body, the second channel fluidly coupling the second buried cavity with the first chamber.

2. A pressure sensor according to claim 1, wherein the first deformable element has a first surface facing the first buried cavity and a second surface opposite to the first surface and facing the first chamber, and wherein the second deformable element has a first surface facing the second buried cavity and a second surface opposite to the first surface and facing the second chamber. 3 . The pressure sensor of claim 1 , wherein the first sensing structure is a structure suspended in the first chamber. The pressure sensor according to claim 3 , wherein the second detection structure is a structure suspended in the second chamber. 5 . The pressure sensor of claim 1 , comprising at least one opening extending through the body, the at least one opening coupling one of the first chamber and the second chamber to an external pressure.

6. The pressure sensor of claim 5, further comprising a second opening extending through the body and coupling the second chamber to a second external pressure fluid, and wherein the at least one opening is a first opening coupling the first chamber to the external pressure fluid. 7 . The pressure sensor according to claim 1 , wherein the body comprises a lower substrate, an upper substrate, and a bonding area hermetically coupling the upper substrate with the lower substrate.

8. The pressure sensor according to claim 1 further includes at least one first transducer element and at least one second transducer element, wherein the at least one first transducer element is configured to detect the deformation of the first deformable element during operation, and the at least one second transducer element is configured to detect the deformation of the second deformable element during operation.

9. The pressure sensor according to claim 8, wherein the at least one first transducer element is sensitive to the deformation direction of the first deformable element, and the at least one second transducer element is sensitive to the deformation direction of the second deformable element.

10. The pressure sensor of claim 8, wherein the at least one first transducing element is a piezoresistor. The pressure sensor of claim 10 , wherein the at least one second transducing element is a piezoresistor.

12. The pressure sensor of claim 1, further comprising a detection circuit configured to perform a differential reading of the deformation of the first deformable element and the deformation of the second deformable element in operation.

13. A pressure sensor, comprising: a first substrate, the first substrate comprising a surface; a first chamber extending into the surface of the first substrate; a second chamber extending into the surface of the first substrate; a wall portion between the first chamber and the second chamber, the wall portion partially defining the first chamber and partially defining the second chamber; a bonding region, the bonding region being on the surface of the first substrate; a second substrate coupled to the first substrate by the bonding region; a first elastic element extending from the wall portion into the first chamber; a second elastic element extending from the wall portion into the second chamber; a first detection structure, the first detection structure being coupled to the first elastic element; a second detection structure, the second detection structure coupled to the second elastic element; a first buried cavity, wherein the first buried cavity is within the first detection structure; a first passage in fluid communication with the first buried cavity, extending through the first elastic element, and extending through the wall portion; a first opening extending into the surface, in fluid communication with the second chamber, and fluidly coupled to the first channel; a second buried cavity, wherein the second buried cavity is within the second detection structure; a second passage in fluid communication with the second buried cavity, extending through the second elastic element, and extending through the wall portion; as well as A second opening extends into the surface, is in fluid communication with the first chamber, and is fluidly coupled to the second channel. 14 . The pressure sensor of claim 13 , further comprising a third opening extending through the second substrate and fluidly coupled to the first chamber. 15 . The pressure sensor of claim 14 , further comprising a fourth opening extending through the second substrate and fluidly coupled to the second chamber. 16 . The pressure sensor of claim 13 , further comprising a third opening extending through the first substrate and fluidly coupled to the first chamber. 17 . The pressure sensor of claim 14 , further comprising a fourth opening extending through the first substrate and fluidly coupled to the second chamber.

18. A pressure sensor comprising: a first substrate comprising a surface, a first chamber extending into the surface, and a wall portion partially defining the first chamber; a first elastic element extending from the wall portion into the first chamber; a first detection structure, the first detection structure being coupled to the first elastic element, the first detection structure being suspended in the first chamber by the first elastic element; a first buried cavity, wherein the first buried cavity is within the first detection structure; a first passage in fluid communication with the first buried cavity, the first passage extending through the first elastic element and through the wall portion; as well as A first opening extends into the surface, the first opening being in fluid communication with the second chamber and fluidly coupled to the first channel.

19. The pressure sensor of claim 18, wherein the first substrate comprises a second chamber, the second chamber being separated from the first chamber by the wall portion, and the wall portion partially defines the second chamber, and the pressure sensor further comprises: a second elastic element extending from the wall portion into the second chamber; a second detection structure, the second detection structure being coupled to the second elastic element, the second detection structure being suspended in the second chamber by the second elastic element; a second buried cavity, wherein the second buried cavity is within the second detection structure; a second passage in fluid communication with the second buried cavity, the second passage extending through the second elastic element and through the wall portion; A second opening extends into the surface, the second opening.

20. The pressure sensor according to claim 19, further comprising: a bonding region on the surface of the first substrate and overlapping the wall portion; as well as A second substrate is coupled to the first substrate by the bonding region.

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