WO2024087110A1 - Capteur de pression de système microélectromécanique avec élément de détection de pression ayant un matériau à changement de phase - Google Patents

Capteur de pression de système microélectromécanique avec élément de détection de pression ayant un matériau à changement de phase Download PDF

Info

Publication number
WO2024087110A1
WO2024087110A1 PCT/CN2022/128013 CN2022128013W WO2024087110A1 WO 2024087110 A1 WO2024087110 A1 WO 2024087110A1 CN 2022128013 W CN2022128013 W CN 2022128013W WO 2024087110 A1 WO2024087110 A1 WO 2024087110A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
pressure sensing
phase
change material
sensing element
Prior art date
Application number
PCT/CN2022/128013
Other languages
English (en)
Inventor
Shao-Fu Sanford Chu
Original Assignee
Yangtze Advanced Memory Industrial Innovation Center Co., Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yangtze Advanced Memory Industrial Innovation Center Co., Ltd filed Critical Yangtze Advanced Memory Industrial Innovation Center Co., Ltd
Priority to PCT/CN2022/128013 priority Critical patent/WO2024087110A1/fr
Publication of WO2024087110A1 publication Critical patent/WO2024087110A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
    • G01L9/0041—Transmitting or indicating the displacement of flexible diaphragms
    • G01L9/0051—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance
    • G01L9/0058—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance of pressure sensitive conductive solid or liquid material, e.g. carbon granules

Definitions

  • the present disclosure relates to microelectromechanical system (MEMS) pressure sensor and fabrication and operating method thereof.
  • MEMS microelectromechanical system
  • Pressure sensors are used for control and monitoring in many fields, including personal electronics, wearables, industrial, and automotive applications.
  • a pressure sensor usually acts as a transducer, which generates a signal, such as an electrical signal, as a function of the pressure imposed.
  • gauge pressure sensors measure the pressure relative to atmospheric pressure.
  • MEMS is a technology used to create miniaturized integrated devices or systems that combine mechanical and electrical components using integrated circuit (IC) batch fabrication techniques for sensing or actuating.
  • IC integrated circuit
  • MEMS pressure sensors inherit the features of MEMS technology, including small size, low cost, etc.
  • a MEMS pressure sensor includes a diaphragm, and a pressure sensing element on the diaphragm and having a phase-change material.
  • the resistivity of the phase-change material changes as a pressure applied to the diaphragm changes.
  • the phase-change material includes a chalcogenide glass.
  • the chalcogenide glass includes at least one of germanium-antimony-tellurium (GeSbTe) , germanium-tellurium (GeTe) , antimony-tellurium (SbTe) , silver-indium-antimony-tellurium (AgInSbTe) , or germanium-antimony (GeSb) .
  • the chalcogenide glass includes GeSb 2 Te 4 (GST) .
  • the MEMS pressure sensor further includes a state setting element electrically coupled to the pressure sensing element and configured to set a state of the phase-change material.
  • the state setting element is configured to apply a first electrical signal to the pressure sensing element to set the phase-change material to a crystalline state, or apply a second electrical signal to the pressure sensing element to set the phase-change material to an amorphous state.
  • the first electrical signal has a lower magnitude and a longer duration than the second electrical signal.
  • the MEMS pressure sensor further includes a resistance measuring element electrically coupled to the pressure sensing element and configured to measure a resistance of the pressure sensing element under the pressure.
  • the pressure is greater than 5 GPa.
  • the MEMS pressure sensor further includes a silicon substrate supporting the diaphragm.
  • a pressure sensing device in another aspect, includes a MEMS pressure sensor, and a logic chip electrically coupled to the MEMS pressure sensor.
  • the MEMS pressure sensor includes a diaphragm, a pressure sensing element on the diaphragm and having a phase-change material, a state setting element electrically coupled to the pressure sensing element, and a resistance measuring element electrically coupled to the pressure sensing element.
  • the resistivity of the phase-change material changes as a pressure applied to the diaphragm changes.
  • the state setting element is configured to set a state of the phase-change material.
  • the resistance measuring element is configured to measure a resistance of the pressure sensing element under the pressure.
  • the phase-change material includes a chalcogenide glass.
  • the chalcogenide glass includes at least one of GeSbTe, GeTe, SbTe, AgInSbTe, or GeSb.
  • the chalcogenide glass includes GST.
  • the setting circuit is configured to control the state setting element to apply a first electrical signal to the pressure sensing element to set the phase-change material to a crystalline state, or control the state setting element to apply a second electrical signal to the pressure sensing element to set the phase-change material to an amorphous state.
  • the first electrical signal has a lower magnitude and a longer duration than the second electrical signal.
  • the pressure sensing element includes a first pressure sensing element having a first phase-change material set at the crystalline state, and a second pressure sensing element having a second phase-change material set at the amorphous state.
  • the measuring circuit is configured to control the resistance measuring element to measure the resistances of the first and second pressure sensing elements, respectively, under the pressure, and determine the pressure based on the measured resistances.
  • the measuring circuit is configured to control the resistance measuring element to apply a voltage signal to the pressure sensing element, and control the resistance measuring element to sense a current signal through the pressure sensing element caused by the applied voltage signal.
  • the pressure is greater than 5 GPa.
  • a method for forming a MEMS pressure sensor is disclosed.
  • a diaphragm is formed from a substrate.
  • a pressure sensing element having a phase-change material is formed on the diaphragm.
  • a resistivity of the phase-change material changes as a pressure applied to the diaphragm changes.
  • the phase-change material includes a chalcogenide glass.
  • the chalcogenide glass includes at least one of GeSbTe, GeTe, SbTe, AgInSbTe, or GeSb.
  • the chalcogenide glass includes GST.
  • a layer of the phase-change material is deposited on the diaphragm, and the layer of the phase-change material is patterned.
  • the layer of the phase-change material is deposited using physical vapor deposition (PVD) .
  • PVD physical vapor deposition
  • the substrate is wet etched.
  • a method for operating a MEMS pressure sensor includes a diaphragm, and a pressure sensing element on the diaphragm and having a phase-change material.
  • the phase-change material is set to a crystalline state or an amorphous state.
  • a pressure is applied on the diaphragm.
  • a resistance of the pressure sensing element having the phase-change material under the pressure is measured. The pressure is determined based on the measured resistance.
  • a first electrical signal is applied to the pressure sensing element to set the phase-change material to the crystalline state, or a second electrical signal is applied to the pressure sensing element to set the phase-change material to the amorphous state.
  • the first electrical signal has a lower magnitude and a longer duration than the second electrical signal.
  • FIG. 1A illustrates a side view of a cross-section of an exemplary MEMS pressure sensor, according to some implementations of the present disclosure.
  • FIG. 1B illustrates a side view of a cross-section of another exemplary MEMS pressure sensor, according to some implementations of the present disclosure.
  • FIG. 1C illustrates a plan view of the MEMS pressure sensors in FIGs. 1A and 1B, according to some implementations of the present disclosure.
  • FIG. 2 illustrates an exemplary curve of change of resistivity of GSTs as the pressure changes, according to some implementations of the present disclosure.
  • FIG. 3 illustrates another plan view of the MEMS pressure sensors in FIGs. 1A and 1B, according to some implementations of the present disclosure.
  • FIG. 4A illustrates a perspective view of a cross-section of an exemplary pressure sensing element having a phase-change material in the crystalline state, according to some implementations of the present disclosure.
  • FIG. 4B illustrates a perspective view of a cross-section of another exemplary pressure sensing element having a phase-change material in the amorphous state, according to some implementations of the present disclosure.
  • FIG. 5 illustrates a block diagram of an exemplary pressure sensing device including the MEMS pressure sensors in FIGs. 1A and 1B, according to some implementations of the present disclosure.
  • FIG. 6 illustrates the waveform diagram of exemplary electrical signals for setting the phase-change materials in the pressure sensing elements into the crystalline state and the amorphous state, respectively, according to some implementations of the present disclosure.
  • FIG. 7 illustrates still another plan view of the MEMS pressure sensors in FIGs. 1A and 1B, according to some implementations of the present disclosure.
  • FIG. 8 illustrates an exemplary I-V curve for measuring the resistance of a pressure sensing element having a phase-change material, according to some implementations of the present disclosure.
  • FIG. 9A illustrates a side view of a cross-section of an exemplary pressure sensing device including the MEMS pressure sensor in FIG. 1A, according to some implementations of the present disclosure.
  • FIG. 9B illustrates a side view of a cross-section of another exemplary pressure sensing device including the MEMS pressure sensor in FIG. 1A, according to some implementations of the present disclosure.
  • FIG. 10 illustrates a flowchart of an exemplary method for operating a MEMS pressure sensor, according to some embodiments of the present disclosure.
  • FIGs. 11A–11E illustrate an exemplary fabrication process for forming a MEMS pressure sensor, according to some implementations of the present disclosure.
  • FIG. 12 illustrates a flowchart of an exemplary method for forming a MEMS pressure sensor, according to some implementations of the present disclosure.
  • terminology may be understood at least in part from usage in context.
  • the term “one or more” as used herein, depending at least in part upon context may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense.
  • terms, such as “a, ” “an, ” or “the, ” again, may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context.
  • the term “based on” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.
  • spatially relative terms such as “beneath, ” “below, ” “lower, ” “above, ” “upper, ” and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element (s) or feature (s) as illustrated in the figures.
  • the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.
  • the apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.
  • the term “substrate” refers to a material onto which subsequent material layers are added.
  • the substrate itself can be patterned. Materials added on top of the substrate can be patterned or can remain unpatterned.
  • the substrate can include a wide array of semiconductor materials, such as silicon, germanium, gallium arsenide, indium phosphide, etc.
  • the substrate can be made from an electrically non-conductive material, such as a glass, a plastic, or a sapphire wafer.
  • a layer refers to a material portion including a region with a thickness.
  • a layer can extend over the entirety of an underlying or overlying structure or may have an extent less than the extent of an underlying or overlying structure. Further, a layer can be a region of a homogeneous or inhomogeneous continuous structure that has a thickness less than the thickness of the continuous structure. For example, a layer can be located between any pair of horizontal planes between, or at, a top surface (e.g., a first surface) and a bottom surface (e.g., a second surface) of the continuous structure. A layer can extend horizontally, vertically, and/or along a tapered surface.
  • a substrate can be a layer, can include one or more layers therein, and/or can have one or more layer thereupon, thereabove, and/or therebelow.
  • a layer can include multiple layers.
  • an interconnect layer can include one or more conductor and contact layers (in which interconnect lines and/or via contacts are formed) and one or more dielectric layers.
  • MEMS pressure sensors Measuring high local pressure, for example, in the gigapascal (GPa) range, using MEMS pressure sensors is challenging.
  • MEMS pressure sensors such as piezoresistive pressure sensors, are not suitable for pressure greater than 5 GPa due to their physical size limit.
  • Quantum-well pressure sensors based on optical spectra shift in photoluminescence show high resolution up to 5 GPa but are complicated to fabricate and operate.
  • phase-change materials such as chalcogenide glasses (a.k.a., chalcogenide alloys) as the material of pressure sensing elements in MEMS pressure sensors, which exhibit a reasonably good resolution in a relatively large high-pressure range, such as between 1 GPa and 10 GPa.
  • Phase-change materials such as GeSb 2 Te 4 (GST)
  • GST GeSb 2 Te 4
  • a pressure sensor of small size can thus be made with the phase-change material using MEMS technology and operated in a relative ease manner.
  • the present disclosure provides pressure sensing devices that integrate the MEMS pressure sensor and a digital conditioning chip, compensating the drift, sensitivity, and linearity parameters digitally.
  • FIG. 1A illustrates a side view of a cross-section of an exemplary MEMS pressure sensor 100, according to some implementations of the present disclosure.
  • MEMS pressure sensor 100 can include a diaphragm 104 (a.k.a., membrane) supported by a substrate 102, which can include silicon (e.g., single crystalline silicon) , silicon germanium (SiGe) , gallium arsenide (GaAs) , germanium (Ge) , silicon on insulator (SOI) , or any other suitable materials.
  • substrate 102 supporting diaphragm 104 is a (100) or (110) oriented silicon substrate.
  • x and y axes are included in FIG. 1A to illustrate two orthogonal directions in the wafer plane. It is noted that z-axis is also included in FIG. 1A to further illustrate the spatial relationship of the components in MEMS pressure sensor 100.
  • Substrate 102 of MEMS pressure sensor 100 includes two lateral surfaces extending laterally in the x-y plane: a top surface on the front side of the wafer, and a bottom surface on the backside opposite to the front side of the wafer.
  • the z-axis is perpendicular to both the x and y axes.
  • one component e.g., a layer or a device
  • another component e.g., a layer or a device
  • the substrate of the device in the z-direction the vertical direction perpendicular to the x-y plane
  • the substrate is positioned in the lowest plane of the device in the z-direction.
  • diaphragm 104 can be formed from substrate 102 by etching substrate 102, for example, using anisotropic wet etching.
  • diaphragm 104 is the remaining film of substrate 102 after etching and is supported by other remaining portions of substrate 102 after etching, according to some implementations.
  • the material of diaphragm 104 thus can be the same as substrate 102, for example, single crystalline silicon.
  • the thickness of diaphragm 104 can vary, for example, depending on the material properties (e.g., Young’s modulus) and the pressure range.
  • the thickness of diaphragm 104 is between 1 ⁇ m and 100 ⁇ m, such as between 10 ⁇ m and 50 ⁇ m (e.g., 10 ⁇ m, 15 ⁇ m, 20 ⁇ m, 25 ⁇ m, 30 ⁇ m, 35 ⁇ m, 40 ⁇ m, 45 ⁇ m, 50 ⁇ m, any range bounded by the lower end by any of these values, or in any range defined by any two of these values) .
  • Diaphragm 104 can deform due to the pressure applied thereto.
  • the deformation-pressure dependence of diaphragm 104 can be abstracted as a side-clamped supported plate under the effect of pressure.
  • MEMS pressure sensor 100 can also include one or more pressure sensing element (s) 106 on diaphragm 104, which has a phase-change material.
  • the resistivity of the phase-change material changes as the pressure applied to diaphragm 104 (and pressure sensing element 106 thereon) changes.
  • the phase-change material of pressure sensing element 106 can exhibit a pressure-resistivity correlation for pressure sensing.
  • a phase-change material is a substance that can change states (phases) between at least an amorphous state and a crystalline state with different resistivities based on heating and quenching of the phase-change material electrothermally.
  • the phase-change material can include a chalcogenide glass, which including one or more chalcogens (sulfur (S) , selenium (Se) , and tellurium (Te) , but excluding oxygen (O) ) .
  • chalcogenide glass which including one or more chalcogens (sulfur (S) , selenium (Se) , and tellurium (Te) , but excluding oxygen (O) ) .
  • the chalcogenide glass includes at least one of germanium-antimony-tellurium (GeSbTe) , such as GeSb 2 Te 4 (GST) , Ge 2 Sb 2 Te 5 , Ge 1 Sb 4 Te 7 , or Ge 1 Sb 2 Te 4 , germanium-tellurium (GeTe) , antimony-tellurium (SbTe) , such as Sb 2 Te 3 , silver-indium-antimony-tellurium (AgInSbTe) , or germanium-antimony (GeSb) , such as Ge 15 Sb 85 .
  • germanium-antimony-tellurium GeSb 2 Te 4 (GST)
  • Ge 2 Sb 2 Te 5 Ge 2 Sb 2 Te 5
  • Ge 1 Sb 4 Te 7 Ge 1 Sb 2 Te 4
  • germanium-tellurium GeTe
  • antimony-tellurium SbTe
  • silver-indium-antimony-tellurium AgInSbTe
  • the strain and/or stress applied to the phase-change material of pressure sensing element 106 due to the deformation of diaphragm 104 when being subject to the pressure can cause the change of the resistivity of the phase-change material as well.
  • the phase-change material of pressure sensing element 106 may include GeSb 2 Te 4 (GST) .
  • GST can exhibit orders-of-magnitude resistivity changes when it is subject to high pressure from 1 GPa to 18 GPa.
  • phase-change material Unlike thermally induced phase changes as commonly known in phase-change material, high pressure changes the bond strength of crystalline GST (c-GST) , and also changes the fraction of vacancies/voids in amorphous GST (a-GST) at a pressure below 7 GPa. At pressure higher than 7 GPa, a-GST turns into a metallic semiconductor glass, which exhibits a very low resistivity.
  • pressure sensing element 106 is capable of sensing a pressure greater than 5 GPa, such as between 5 GPa and 10 GPa, according to some implementations. In some implementations, pressure sensing element 106 has a pressure sensing range between 1 GPa and 10 GPa.
  • the change of resistivity of the phase-change material due to the change of pressure also causes the change of resistance of pressure sensing element 106, according to some implementations, That is, the resistance of pressure sensing element 106 having the phase-change material can change as the pressure applied to diaphragm 104 changes.
  • pressure sensing element 106 can be disposed within diaphragm 104, such that the deformation of diaphragm 104 due to applied pressure can cause stress and/or strain to pressure sensing element 106 to change the resistivity of the phase-change material and the resistance of pressure sensing element 106.
  • the planar dimensions and shapes of pressure sensing element 106 as well as diaphragm 104 can vary in different applications due to different design needs and requirements.
  • diaphragm 104 may have a square, rectangular, or circular planar shape.
  • pressure sensing element 106 may have a square shape extending along any suitable planar direction (e.g., x-direction or y-direction) .
  • pressure sensing elements 106 may vary as well.
  • at least two pressure sensing elements 106A and 106B may be disposed with the same diaphragm 104 along two orthogonal directions (e.g., x-direction or y-direction) to sense the pressure components in different directions.
  • pressure sensing element 106A may mainly undergo longitudinal stress
  • pressure sensing element 106B may mainly undergo transverse stress.
  • the number of diaphragms 104 may vary as well.
  • MEMS pressure sensor 100 may include multiple diaphragm 104 (e.g., in rotated positions) , and one or more pressure sensing elements 106 may be disposed on each diaphragm 104 to form an array of diaphragm 104 and an array of pressure sensing elements 106 to fully characterize the pressure components in different directions.
  • MEMS pressure sensor 100 is a gauge pressure sensor that measures the pressure relative to atmospheric pressure (e.g., 1 standard atmosphere “atm” ) .
  • the top surface of diaphragm 104 on which pressure sensing element 106 is formed can be sealed in a package, such that the pressure applied to the top surface of diaphragm 104 can be maintained at atmospheric pressure.
  • the bottom surface of diaphragm 104 opposite the top surface can be exposed to the pressure to be measured relative to atmospheric pressure.
  • MEMS pressure sensor 100 further includes a supporting structure 108 bonded to substrate 102 to form a cavity 110 surrounded by the bottom surface of diaphragm 104, substrate 102, and supporting structure 108.
  • Supporting structure 108 can include any suitable materials that can be bonded to substrate 102, such as a glass wafer when substrate 102 is a silicon substrate.
  • FIG. 1B illustrates another MEMS pressure sensor 101 that measures the pressure relative to atmospheric pressure.
  • a cavity 111 can be completely sealed by the bottom surface of diaphragm 104, substrate 102, and a sealing structure 109 without any opening therethrough to maintain the pressure in cavity 111 at atmospheric pressure.
  • the top surface of diaphragm 104 on which pressure sensing element 106 is formed can be exposed to the pressure to be measured relative to atmospheric pressure.
  • the same components in MEMS pressure sensors 100 and 101 are not repeated in describing FIG. 1B for ease of description.
  • pressure sensing element 106 has two terminals configured to receive and transmit an electrical signal, such as a voltage signal applied to pressure sensing element 106 or a current signal through pressure sensing element 106.
  • each terminal of pressure sensing element 106 is implemented by an electrode as shown, for example, in FIGs. 4A and 4B.
  • pressure sensing element 106 can be stacked vertically between a bottom electrode 402 and a top electrode 404.
  • top electrode 404 may be above and in contact with pressure sensing element 106
  • bottom electrode 402 may be below and in contact with pressure sensing element 106.
  • Electrodes 402 and 404 can include conductive materials including, but not limited to, tungsten (W) , cobalt (Co) , copper (Cu) , aluminum (Al) , carbon, polysilicon, doped silicon, silicides, or any combination thereof.
  • each electrode 402 or 404 includes titanium nitride (TiN) .
  • the phase-change material of pressure sensing element 106 can switch between the crystalline state and the amorphous state based on heating and quenching of the phase-change materials electrothermally.
  • a current signal can be applied through electrodes 402 and 404 to switch the phase-change material (or at least a fraction of it that blocks the current path) of pressure sensing element 106 between the two states (e.g., the crystalline state in FIG. 4A and the amorphous state in FIG. 4B) .
  • FIG. 5 illustrates a block diagram of an exemplary pressure sensing device 500 including MEMS pressure sensors 100 and 101 in FIGs. 1A and 1B, according to some implementations of the present disclosure.
  • pressure sensing device 500 can also include a logic chip 502 configured to control operations of MEMS pressure sensor 100 or 101 to obtain sensing signals and to process the sensing signals obtained by MEMS pressure sensor 100 or 101.
  • pressure sensing device 500 may integrate MEMS pressure sensor 100 or l01 and logic chip 502 for compensating the drift, sensitivity, and linearity parameters digitally.
  • MEMS pressure sensor 100 or 101 can also include a state setting element 504 electrically coupled to the two terminals (e.g., through electrodes 402 and 404) of pressure sensing element 106.
  • a state setting element 504 electrically coupled to the two terminals (e.g., through electrodes 402 and 404) of pressure sensing element 106.
  • the phase-change material of pressure sensing element 106 can exhibit different pressure-resistivity characteristics (e.g., the linear range, resolution/sensitivity, etc. ) when it is set to different states (e.g., the crystalline state and the amorphous state) .
  • State setting element 504 can be configured to set the state of the phase-change material.
  • state setting element 504 is configured to apply an electrical signal to pressure sensing element 106 to set the phase-change material to either the crystalline state or the amorphous state, depending on the properties of the electrical signal.
  • state setting element 504 may be configured to apply a first electrical signal to pressure sensing element 106 to set the phase-change material to the crystalline state (e.g., in FIG. 4A) , or apply a second electrical signal to pressure sensing element 106 to set the phase-change material to the amorphous state (in FIG. 4B) .
  • the first electrical signal has a lower magnitude and a longer duration than the second electrical signal. That is, a relatively short and high current/voltage signal can be used by state setting element 504 to heat up the phase-change material to melt and quench molten material into the amorphous state, while a relatively long and low current/voltage signal can be used by state setting element 504 to heat up the phase-change material to crystallize the amorphous material into the crystalline state.
  • the first electrical signal may be voltage pulse 1
  • the second electrical signal may be voltage pulse 2
  • the duration of voltage pulse 1 may be longer than the duration of voltage pulse 2
  • the voltage magnitude of voltage pulse 1 may be lower than the voltage magnitude of voltage pulse 2.
  • the voltage magnitude of voltage pulse 2 may be high enough to heat up the phase-change material to above the melting temperature (T melt ) , and the voltage magnitude of voltage pulse 2 may be high enough to heat up the phase-change material to be above the crystallizing temperature (T cyst ) , but below the melting temperature.
  • the phase-change materials of different pressure sensing elements 106 disposed on the same diaphragm 104 are set to different states for cross-check/calibration purposes.
  • a first pressure sensing element 106C may have a first phase-change material set at the crystalline state (e.g., c-GST)
  • a second pressure sensing element 106D may have a second phase-change material set at the amorphous state (e.g., a-GST) , both of which may be disposed on the same diaphragm 104 to measure the same pressure.
  • logic chip 502 can include a setting circuit 508 electrically coupled to state setting element 504 of MEMS pressure sensor 100 or 101.
  • Setting circuit 508 can be configured to control state setting element 504 to apply the electrical signal to pressure sensing element 106 to set the state of the phase-change material.
  • setting circuit 508 is configured to determine the magnitude and duration of the electrical signal based on the desired state of the phase-change material, as described above, and to control state setting element 504 to apply the electrical signal with the determined magnitude and duration to pressure sensing element 106.
  • setting circuit 508 may be configured to control state setting element 504 to apply the first electrical signal to pressure sensing element 106 to set the phase-change material to the crystalline state, or control state setting element 504 to apply the second electrical signal to pressure sensing element 106 to set the phase-change material to the amorphous state.
  • MEMS pressure sensor 100 or 101 can further include a resistance measuring element 506 electrically coupled to the two terminals (e.g., through electrodes 402 and 404) of pressure sensing element 106.
  • Resistance measuring element 506 can be configured to measure the resistance of pressure sensing element 106 under the pressure, for example, based on the current-voltage (I-V) curve of pressure sensing element 106.
  • resistance measuring element 506 is configured to apply a voltage signal to pressure sensing element 106, and then sense a current signal through pressure sensing element 106 caused by the applied voltage signal.
  • pressure sensing element 106 having phase-change material in the crystalline state and/or the amorphous state behaviors as a resistor can be used to measure the resistance of pressure sensing element 106 based on the voltage applied to pressure sensing element 106 and the induced current through pressure sensing element 106.
  • the resistance of pressure sensing element 106 changes in the same manner as the resistivity of the phase-change material changes as the pressure changes, according to some implementations.
  • logic chip 502 can also include a measuring circuit 510 electrically coupled to resistance measuring element 506 of MEMS pressure sensor 100 or 101.
  • Measuring circuit 510 can be configured to control resistance measuring element 506 to measure the resistance of pressure sensing element 106 under the pressure, and determine the pressure based on the measured resistance.
  • measuring circuit 510 is configured to control resistance measuring element 506 to apply the voltage signal to pressure sensing element 106, and control resistance measuring element 506 to sense the current signal through pressure sensing element 106 caused by the applied voltage signal.
  • measuring circuit 510 may be configured to determine the magnitudes of the voltage signals to be applied to pressure sensing element 106, and calculate the resistance (e.g., the slope of the I-V curve) of pressure sensing element 106 based on the magnitudes of the voltage signals and the corresponding magnitudes of the sensed current signals through pressure sensing element 106.
  • the resistance e.g., the slope of the I-V curve
  • Measuring circuit 510 can further determine the applied pressure based on the measured resistance of pressure sensing element 106. In some implementations, measuring circuit 510 calculates the resistivity of the phase-change material of pressure sensing element 106 based on the resistance and dimensions of pressure sensing element 106, and then determines the pressure corresponding to the calculated resistivity based on the pressure-resistivity characteristics of the phase-change material in the corresponding state (e.g., as shown in FIG. 2) .
  • the resolution/sensitivity of MEMS pressure sensors having phase-change materials as disclosed herein can be much higher, for example, orders-of-magnitude resistivity change between 1 GPa and 10 GPa for GST (e.g., as shown in FIG. 2) .
  • the resistance changes of a single pressure sensing element 106 can be large enough to be measured directly without using any signal amplification means, such as the Wheatstone bridge circuit, which is commonly used in piezoresistive MEMS pressure sensors.
  • logic chip 502 may include microprocessors, microcontroller units (MCUs) , digital signal processors (DSPs) , application-specific integrated circuits (ASICs) , field-programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout the present disclosure. It is also understood that in addition to setting circuit 508 and measuring circuit 510 described above, logic chip 502 may further include any suitable circuits that can facilitate the operations and/or improve the performance of MEMS pressure sensor 100 or 101, such as drift compensating circuits, temperature compensating circuit, calibration circuit, etc.
  • MCUs microcontroller units
  • DSPs digital signal processors
  • ASICs application-specific integrated circuits
  • FPGAs field-programmable gate arrays
  • PLDs programmable logic devices
  • state machines gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout the present disclosure.
  • Pressure sensing device 500 can be implemented in any suitable configuration and packaging.
  • FIG. 9A illustrates a side view of a cross-section of an exemplary pressure sensing device 900 including MEMS pressure sensor 100 in FIG. 1A, according to some implementations of the present disclosure.
  • Pressure sensing device 900 can include a package substrate 902, such as a ceramic substrate or a printed circuit board (PCB) , on which MEMS pressure sensor 100 and logic chip 502 are mounted.
  • MEMS pressure sensor 100 can be a gauge pressure sensor for backside pressure measurement. Atmospheric pressure can be applied to the top surface of diaphragm 104, and the pressure to be measured can be applied to the bottom surface of diaphragm 104 through cavity 110. As shown in FIG.
  • pressure sensing device 900 can also include a package cap 906 that completely encapsulates the top and sides of MEMS pressure sensor 100 to form a cavity 910 in which atmospheric pressure can be maintained.
  • an opening 904 can be made through package substrate 902 to be connected to cavity 110 to allow external pressure to be applied to the bottom surface of diaphragm 104.
  • pressure sensing device 900 can include any other suitable components, such as discrete components 908 (e.g., capacitors) that can be electrically connected to MEMS pressure sensor 100 and logic chip 502 through the electrical connections on package substrate 902.
  • Pressure sensing device 900 can further include a contact pad 912 electrically connected to MEMS pressure sensor 100, logic chip 502, and/or discrete components 908 to make electrical connections to external devices.
  • FIG. 9B illustrates a side view of a cross-section of another exemplary pressure sensing device 901 including MEMS pressure sensor 101 in FIG. 1A, according to some implementations of the present disclosure.
  • Pressure sensing device 901 can include a package substrate 903, such as a ceramic substrate or a PCB, on which MEMS pressure sensor 101 and logic chip 502 are mounted.
  • MEMS pressure sensor 101 can be a gauge pressure sensor for frontside pressure measurement. Atmospheric pressure can be maintained in cavity 111 and applied to the bottom surface of diaphragm 104, and the pressure to be measured can be applied to the top surface of diaphragm 104.
  • pressure sensing device 901 can also include any other suitable components, such as discrete components 908 (e.g., capacitors) that can be electrically connected to MEMS pressure sensor 101 and logic chip 502 through the electrical connections on package substrate 903.
  • Pressure sensing device 901 can further include contact pad 912 electrically connected to MEMS pressure sensor 101, logic chip 502, and/or discrete components 908 to make electrical connections to external devices.
  • FIG. 10 illustrates a flowchart of an exemplary method 1000 for operating a MEMS pressure sensor, according to some embodiments of the present disclosure.
  • the MEMS pressure sensor includes MEMS pressure sensors 100 and 101 depicted in FIGs. 1A and 1B or any other suitable MEMS pressure sensor that includes a diaphragm, and a pressure sensing element on the diaphragm and having a phase-change material, where the resistivity of the phase-change material changes as the pressure applied to the diaphragm changes.
  • the operations shown in method 1000 are not exhaustive and that other operations can be performed as well before, after, or between any of the illustrated operations. Further, some of the operations may be performed simultaneously, or in a different order than shown in FIG. 10.
  • method 1000 starts at operation 1002, in which the phase-change material of the pressure sensing element in the MEMS pressure sensor is set to a crystalline state or an amorphous state.
  • a first electrical signal is applied to the pressure sensing element to set the phase-change material to the crystalline state, or a second electrical signal is applied to the pressure sensing element to set the phase-change material to the crystalline state.
  • the first electrical signal can have a lower magnitude and a longer duration than the second electrical signal.
  • setting circuit 508 of logic chip 502 controls state setting element 504 of MEMS pressure sensor 100 or 101 to apply a corresponding electrical signal (e.g., voltage pulse 1 or 2 in FIG. 6) to pressure sensing element 106 to set the state of the phase-change material.
  • Method 1000 proceeds to operation 1004, as illustrated in FIG. 10, in which a pressure is applied to the diaphragm.
  • the MEMS pressure sensor is a gauge pressure sensor, and the pressure is applied to either the top surface or the bottom surface of the diaphragm for frontside pressure measurement or backside pressure measurement relative to atmospheric pressure that is maintained in a cavity.
  • the pressure to be measured is applied to the bottom surface and the top surface of diaphragm 104, respectively.
  • Method 1000 proceeds to operation 1006, as illustrated in FIG. 10, in which the resistance of the pressure sensing element having the phase-change material is measured under the pressure.
  • a voltage signal is applied to the pressure sensing element, and a current signal through the pressure sensing element caused by the applied voltage signal is sensed.
  • measuring circuit 510 of logic chip 502 controls resistance measuring element 506 of MEMS pressure sensor 100 or 101 to apply a voltage signal to pressure sensing element 106, and controls resistance measuring element 506 of MEMS pressure sensor 100 or 101 to sense the current signal through the pressure sensing element caused by the applied voltage signal.
  • the resistance of pressure sensing element 106 under the pressure is measured based on the sense current signal and the applied voltage signal that follow an I-V curve (e.g., shown in FIG. 8) .
  • Method 1000 proceeds to operation 1008, as illustrated in FIG. 10, in which the pressure is determined based on the measured resistance.
  • measuring circuit 510 of logic chip 502 determine the pressure based on the measured resistance of pressure sensing element 106, as well as the dimensions of pressure sensing element 106 and the pressure-resistivity characteristics of the phase-change material in the corresponding state (e.g., shown in FIG. 2) .
  • FIGs. 11A–11E illustrate an exemplary fabrication process for forming a MEMS pressure sensor, according to some implementations of the present disclosure.
  • FIG. 12 illustrates a flowchart of an exemplary method 1200 for forming a MEMS pressure sensor, according to some implementations of the present disclosure. Examples of the MEMS pressure sensor depicted in FIGs. 11A–11E and 12 include MEMS pressure sensors 100 and 101 depicted in FIGs. 1A and 1B. FIGs. 11A–11E and 12 will be described together. It is understood that the operations shown in method 1200 are not exhaustive and that other operations can be performed as well before, after, or between any of the illustrated operations. Further, some of the operations may be performed simultaneously, or in a different order than shown in FIG. 12.
  • a diaphragm can be formed from a substrate.
  • the substrate is etched to form the diaphragm.
  • an etch mask 1104 is formed on the backside of a silicon substrate 1102.
  • Etch mask 1104 can be formed first by oxidizing a portion of silicon substrate 1102 to form a silicon oxide layer, and then by patterning the silicon oxide layer to expose a region in which the diaphragm to be formed.
  • a diaphragm 1108 is formed by anisotropic wet etching of silicon substrate 1102 through etch mask 1104 using any suitable silicon etchants, such as potassium hydroxide (KOH) .
  • KOH potassium hydroxide
  • the thickness of diaphragm 1108 can be controlled by controlling the etching rate and/or etching time.
  • a supporting substrate 1110 such as a glass wafer, is bonded to the backside of silicon substrate 1102 to form a cavity 1106 at the backside of silicon substrate 1102, for example, using anodic bonding. It is understood that for backside pressure measurement, an opening (not shown) may be etched through supporting substrate 1110 using wet etching, dry etching, laser ablation, and/or mechanical drilling.
  • a pressure sensing element having a phase-change material can then be formed on the diaphragm.
  • the resistivity of the phase-change material changes as the pressure applied to the diaphragm changes.
  • a layer of phase-change material is deposited on the diaphragm, for example, using physical vapor deposition (PVD) .
  • PVD physical vapor deposition
  • the bonded structure is flipped upside down to allow physical vapor deposition of a GST layer 1112 on the top surface of diaphragm 1108 at the front side of silicon substrate 1102.
  • GST layer 1112 is deposited using sputtering techniques with three different sputtering targets having Ge, Se, and Te, or a single sputtering target having a GeSeTe alloy.
  • the layer of a phase-change material is patterned to form the pressure sensing element.
  • GST layer 1112 shown in FIG. 11D
  • a pressure sensing element 1114 having the GST material.
  • electrodes such as TiN electrodes (not shown) , may be formed under and above pressure sensing element 1114.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Fluid Pressure (AREA)
  • Pressure Sensors (AREA)

Abstract

Un capteur de pression (100) de système microélectromécanique (MEMS) comprend un diaphragme (104), et un élément de détection de pression (106) sur le diaphragme (104) et ayant un matériau à changement de phase. La résistivité du matériau à changement de phase change lorsqu'une pression appliquée au diaphragme (104) change. Un dispositif de détection de pression comprend un capteur de pression à système microélectromécanique (MEMS) comprenant un diaphragme (104), un élément de détection de pression (106) sur le diaphragme (104) et ayant un matériau à changement de phase, un élément de réglage d'état (504), un élément de mesure de résistance (506), une puce logique (502) comprenant un circuit de réglage (508) et un circuit de mesure (510). L'invention concerne également un procédé de formation d'un capteur de pression (100) de système microélectromécanique (MEMS).
PCT/CN2022/128013 2022-10-27 2022-10-27 Capteur de pression de système microélectromécanique avec élément de détection de pression ayant un matériau à changement de phase WO2024087110A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/128013 WO2024087110A1 (fr) 2022-10-27 2022-10-27 Capteur de pression de système microélectromécanique avec élément de détection de pression ayant un matériau à changement de phase

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/128013 WO2024087110A1 (fr) 2022-10-27 2022-10-27 Capteur de pression de système microélectromécanique avec élément de détection de pression ayant un matériau à changement de phase

Publications (1)

Publication Number Publication Date
WO2024087110A1 true WO2024087110A1 (fr) 2024-05-02

Family

ID=90829607

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/128013 WO2024087110A1 (fr) 2022-10-27 2022-10-27 Capteur de pression de système microélectromécanique avec élément de détection de pression ayant un matériau à changement de phase

Country Status (1)

Country Link
WO (1) WO2024087110A1 (fr)

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1466780A (zh) * 2000-09-29 2004-01-07 株式会社山武 压力传感器和生产压力传感器的方法
US20060137456A1 (en) * 2004-12-27 2006-06-29 Samhita Dasgupta Static and dynamic pressure sensor
CN101131335A (zh) * 2007-09-07 2008-02-27 南京航空航天大学 二维小量程力传感器
US20140089623A1 (en) * 2012-09-26 2014-03-27 Chang W. Ha Column address decoding
CN104596683A (zh) * 2015-02-12 2015-05-06 南京大学 基于层状材料的压力传感器及压电效应测量系统
CN104867876A (zh) * 2014-02-24 2015-08-26 清华大学 薄膜晶体管阵列的制备方法
CN104979464A (zh) * 2015-06-11 2015-10-14 上海电力学院 一种基于石墨烯异质结的柔性热电转换器件
CN105470303A (zh) * 2014-09-30 2016-04-06 台湾积体电路制造股份有限公司 半导体器件及其沟道结构
CN108195492A (zh) * 2018-01-19 2018-06-22 上海电力学院 利用二维相变材料制备的超灵敏应力传感器
CN112229568A (zh) * 2020-11-05 2021-01-15 武汉飞恩微电子有限公司 一种具有诊断功能的压力传感器及其诊断方法

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1466780A (zh) * 2000-09-29 2004-01-07 株式会社山武 压力传感器和生产压力传感器的方法
US20060137456A1 (en) * 2004-12-27 2006-06-29 Samhita Dasgupta Static and dynamic pressure sensor
CN101131335A (zh) * 2007-09-07 2008-02-27 南京航空航天大学 二维小量程力传感器
US20140089623A1 (en) * 2012-09-26 2014-03-27 Chang W. Ha Column address decoding
CN104867876A (zh) * 2014-02-24 2015-08-26 清华大学 薄膜晶体管阵列的制备方法
CN105470303A (zh) * 2014-09-30 2016-04-06 台湾积体电路制造股份有限公司 半导体器件及其沟道结构
CN104596683A (zh) * 2015-02-12 2015-05-06 南京大学 基于层状材料的压力传感器及压电效应测量系统
CN104979464A (zh) * 2015-06-11 2015-10-14 上海电力学院 一种基于石墨烯异质结的柔性热电转换器件
CN108195492A (zh) * 2018-01-19 2018-06-22 上海电力学院 利用二维相变材料制备的超灵敏应力传感器
CN112229568A (zh) * 2020-11-05 2021-01-15 武汉飞恩微电子有限公司 一种具有诊断功能的压力传感器及其诊断方法

Similar Documents

Publication Publication Date Title
US7861575B2 (en) Micro gas sensor and manufacturing method thereof
US6573734B2 (en) Integrated thin film liquid conductivity sensor
US7255001B1 (en) Thermal fluid flow sensor and method of forming same technical field
EP2762866B1 (fr) Capteur de gaz CMOS et son procédé de fabrication
JP2004507728A (ja) 高温回路構成
EP1723720A1 (fr) Resonateur mems a regulation de temperature et procede destine a reguler la frequence d'un resonateur
JPH05273053A (ja) 温度センサおよび該温度センサの製造方法
US20130207069A1 (en) Metal-insulator transition switching devices
US20090085031A1 (en) Wafer-Shaped Measuring Apparatus and Method for Manufacturing the Same
US20210364458A1 (en) Gas sensor
WO2024087110A1 (fr) Capteur de pression de système microélectromécanique avec élément de détection de pression ayant un matériau à changement de phase
US20050050944A1 (en) Sensor and method for manufacturing the same
EP0873500B1 (fr) Structures pour capteurs de temperature et detecteurs a infrarouge
US6423559B2 (en) Integrated circuit and fabricating method and evaluating method of integrated circuit
US7812705B1 (en) High temperature thermistor probe
CN113793870A (zh) 一种半导体器件及其制备方法
KR100421177B1 (ko) 전기도금을 이용한 초소형 열유속 센서 및 그 제조방법
KR19980080155A (ko) 박막 부재를 구비한 센서
JP2011089859A (ja) 温度センサ
KR20100019261A (ko) 산화아연 나노막대 어레이를 이용한 센서 및 그 제조방법
JP2001264188A (ja) 半導体歪ゲージおよび半導体歪ゲージの製造方法
KR102046014B1 (ko) 하이브리드형 수소센서, 그 제조 방법 및 제어 방법
KR100300285B1 (ko) 미세 열유속센서 및 그 제조 방법
WO2017171855A1 (fr) Système piézoélectrique sensible à la contrainte avec indicateur optique
KR20210100502A (ko) 열류 스위칭 소자