CN110745774A - SiC temperature sensor with cantilever beam structure and manufacturing method thereof - Google Patents

SiC temperature sensor with cantilever beam structure and manufacturing method thereof Download PDF

Info

Publication number
CN110745774A
CN110745774A CN201910981318.5A CN201910981318A CN110745774A CN 110745774 A CN110745774 A CN 110745774A CN 201910981318 A CN201910981318 A CN 201910981318A CN 110745774 A CN110745774 A CN 110745774A
Authority
CN
China
Prior art keywords
layer
sic
mask
metal
temperature sensor
Prior art date
Legal status (The legal status 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 status listed.)
Granted
Application number
CN201910981318.5A
Other languages
Chinese (zh)
Other versions
CN110745774B (en
Inventor
周圣军
万泽洪
徐浩浩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wuhan University WHU
Original Assignee
Wuhan University WHU
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 Wuhan University WHU filed Critical Wuhan University WHU
Priority to CN201910981318.5A priority Critical patent/CN110745774B/en
Publication of CN110745774A publication Critical patent/CN110745774A/en
Application granted granted Critical
Publication of CN110745774B publication Critical patent/CN110745774B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
    • G01K7/01—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using semiconducting elements having PN junctions
    • G01K7/015—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using semiconducting elements having PN junctions using microstructures, e.g. made of silicon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
    • B81B7/02—Microstructural systems; Auxiliary parts of microstructural devices or systems containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
    • B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
    • B81C1/00134—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems comprising flexible or deformable structures
    • B81C1/0015—Cantilevers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2201/00—Specific applications of microelectromechanical systems
    • B81B2201/02—Sensors
    • B81B2201/0278—Temperature sensors

Landscapes

  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Pressure Sensors (AREA)
  • Micromachines (AREA)

Abstract

The invention discloses a SiC temperature sensor with a cantilever beam structure and a manufacturing method thereof, wherein the temperature sensor structure comprises: the MEMS device comprises a MEMS cantilever beam with a multilayer structure, a Wheatstone bridge detection circuit and four metal pads. The MEMS cantilever beam with the multilayer structure has a SiC bottom layer, a composite silicon compound middle layer and a top metal layer from bottom to top. The SiC bottom layer comprises three parts: a piezoresistive region, an electrical connection line region, and an undoped region; the composite silicon compound interlayer is formed by stacking a plurality of thin layers of silicon compounds. The Wheatstone bridge detection circuit is formed on the SiC bottom layer through an ion implantation process and consists of a piezoresistive region and an electric connection circuit region, and the electric connection circuit region comprises an electrode and a connection circuit. The SiC temperature sensor can realize accurate measurement of temperature in a high-temperature environment, and not only is insulation protection realized, but also thermal stress damage can be effectively prevented through the composite silicon compound intermediate layer.

Description

SiC temperature sensor with cantilever beam structure and manufacturing method thereof
Technical Field
The invention belongs to the technical field of wide bandgap semiconductor device preparation, relates to a temperature sensor preparation method, and particularly relates to a SiC temperature sensor with a cantilever beam structure and a manufacturing method thereof.
Background
The semiconductor integrated sensor has the characteristics of specific function, small measurement error, high response speed, small volume, micro power consumption, no need of nonlinear calibration and the like. However, the existing semiconductor integrated sensor mostly takes Si-based as a main component, and because the band gap of Si is narrow (1.12 eV), the high temperature resistance and radiation performance are poor, and the high temperature working environment cannot be adapted to, the highest working temperature of the Si-based sensor on the market is about 125 ℃. In addition, Si can react with other substances in a severe environment and is easy to oxidize or corrode; the mechanical properties of Si are susceptible to degradation at high temperatures, and therefore Si-based temperature sensors have not been able to survive in complex and harsh operating environments.
Along with the exploration of people on severe environment, particularly in the field of high-temperature measurement at the temperature of more than 350 ℃, the SiC material has higher requirements on the high-temperature resistance of the temperature sensor, has the excellent material properties of wide band gap, high thermal conductivity, high melting point, excellent mechanical property, radiation resistance, corrosion resistance, high thermal stability, large piezoelectric coefficient, high saturated electron drift rate, low dielectric constant and the like, and is an ideal material for manufacturing the high-temperature resistant sensor.
Common semiconductor integrated temperature sensors include platinum resistor type, thermistor type, thermocouple type, PN junction type, and the like. With the advent of MEMS (Micro-Electro-Mechanical systems ) technology, piezoresistive, piezoelectric, inductive, resonant, polysilicon Micro-bridge, and other MEMS temperature sensors have been developed. The piezoresistive sensor has good sensitivity, small output impedance and high output linearity, so the piezoresistive sensor is very effective in measuring non-electric quantity parameters.
Disclosure of Invention
The invention aims to provide a cantilever beam structured SiC temperature sensor, which ensures that an integrated temperature sensor working in a severe environment has higher reliability, longer service life, better sensitivity and better linearity.
In order to solve the technical problems, the invention adopts the technical scheme that:
the utility model provides a SiC temperature sensor of cantilever beam structure which characterized in that: including SiC bottom, compound silicon compound intermediate level and top metal layer from bottom to top, inject the doping through the ion implantation technology on the Si face of SiC bottom and form Wheatstone bridge detection circuitry, undoped region is the insulation protection region, deposit the conducting metal with Wheatstone bridge detection circuitry's electrode electricity intercommunication on the SiC bottom, form the metal pad, compound silicon compound intermediate level is used for buffering thermal stress, compound silicon compound intermediate level by a plurality of low thermal expansion coefficient, high dielectric constant, high insulating nature, can produce the silicon compound thin layer of different direction stresses after the thermal expansion and pile up and form, make the metal pad expose through selecting the deposition area in compound silicon compound intermediate level, top metal layer and compound silicon compound intermediate level the superiors deposit on compound silicon compound intermediate level superiors with the same area, the etching of the C face middle part of SiC bottom has the cavity, and a pattern penetrating through the top metal layer is etched at the bottom of the cavity to form the MEMS cantilever beam structure.
Furthermore, the wheatstone bridge detection circuit is composed of a piezoresistive region and an electric connection circuit region, the electric connection circuit region comprises electrodes and a connection circuit, the piezoresistive region and the electrodes are interconnected through the connection circuit to form the wheatstone bridge detection circuit, the piezoresistive region comprises four piezoresistor strips, the four piezoresistor strips are a pair of longitudinal piezoresistor strips and a pair of transverse piezoresistor strips, the connection circuit is used for connecting the four piezoresistor strips end to end, and the number of the electrodes is four, and the electrodes are distributed on the connection circuit between the two adjacent piezoresistor strips. The longitudinal piezoresistor strips are parallel to the cantilever structure, the transverse piezoresistor strips are perpendicular to the cantilever structure, the transverse piezoresistor strips and the longitudinal piezoresistor strips are made of N-type or P-type SiC, the transverse piezoresistor strips and the longitudinal piezoresistor strips are processed by a surface layer structure of a SiC bottom layer by adopting an ion implantation doping process, and preferably, phosphorus ions can be adopted as an ion implantation material.
The electric connection circuit area comprises electrodes and a connection circuit, the conductive circuit is formed in a heavily doped mode of ion implantation, the type of implanted ions is the same as that of the piezoresistive area, and the same type of N-type or P-type semiconductor is formed. The electrodes are four in number and are uniformly arranged around the temperature sensor, preferably, rectangular patterns are adopted, and at least one side of each rectangular pattern is longer than 300 mu m, so that the electrodes can be conveniently interconnected with external leads. The undoped region is an undoped SiC bottom layer and can play insulating and protecting roles on a Wheatstone bridge detection circuit.
The composite silicon compound intermediate layer is formed by stacking a plurality of silicon compound thin layers which have low thermal expansion coefficient, high dielectric constant and high insulativity and can generate stress in different directions after thermal expansion, has the function of thermal shock resistance, realizes the protection of the SiC bottom layer, and is used as an insulating layer to separate the top metal layer from a Wheatstone bridge detection circuit on the SiC bottom layer, thereby realizing the protection of the circuit.
Preferably, the composite silicon compound interlayer formed by stacking a plurality of thin layers of silicon compounds can adopt two layers of silicon compounds, and the silicon compounds can adopt SiO2Layer and Si3N4Layers with a thickness of 0.3 + -0.05 μm and 0.2 + -0.02 μm, respectively. SiO 22Compressive stress after thermal expansion of the layer, Si3N4Tensile stress is generated after the layers are thermally expanded, so that the stress concentration phenomenon of the composite silicon compound intermediate layer can be relieved by adopting the two materials. The SiO2The side length of the layer is equal to that of the SiC bottom layer, Si3N4The side length of the layer being less than SiO2The side length of the layer is 300 +/-10 mu m, and a size allowance is reserved for the metal bonding pad so as to realize the connection of the metal bonding pad and an external circuit structure, namely SiO2Four through hole structures are distributed on the layer and used for depositing the metal bonding pad, the through holes are located right above the electrodes, and the length of each through hole is slightly larger than the side length of each electrode by 3-5 microns.
Furthermore, the four piezoresistor strips are prepared by carrying out light doping or middle doping on a local area of the SiC bottom layer through an ion implantation process, the doping type is N type or P type, and the electrodes and the connecting circuit are SiC prepared by carrying out heavy doping of the same type as the piezoresistor strips on the local area of the SiC bottom layer through the ion implantation process.
Furthermore, any two adjacent piezoresistor strips are mutually perpendicular on the extension line, and the four piezoresistor strips are arranged in a unidirectional mode to form a radial shape.
Further, the metal pad is total four, evenly distributed around temperature sensor, the metal pad includes pad bottom metal level and pad top metal level, and electrode top and formation ohmic contact are arranged in to pad bottom metal level, and pad bottom metal level is arranged in pad bottom metal level top and is formed the electrical contact with it, and pad top metal level passes through lead structure connection metal pad and external circuit, and pad top metal level height is resistant to oxidation.
Further, the metal layer at the bottom of the bonding pad is made of metal nickel, metal aluminum or titanium, and the metal layer at the top of the bonding pad is made of metal platinum with high oxidation resistance; pad bottom metal level adopts metal nickel or titanium to make, pad top metal level adopts the metal platinum that has high anti-oxidation characteristic to make, and thickness is 0.05 0.01 mu m, and when the electrode adopted N type to dope, pad bottom metal level can adopt materials such as metal nickel Ni, and when the electrode adopted P type to dope, pad bottom metal level can adopt materials such as metal titanium Ti, and thickness is 0.25 0.02 mu m.
Further, the composite silicon compound intermediate layer includes SiO having opposite stress after thermal expansion2Layer and Si3N4Layer of said SiO2A layer deposited on the SiC bottom layer around the metal pad, the Si3N4Layer deposition on SiO2On the layer.
Further, the top metal layer is made of a metal material with high thermal expansion coefficient, high elastic property and good ductility. Preferably, the top metal layer can be copper Cu with the thickness of 0.5-5 μm.
A preparation method of a cantilever beam structured SiC temperature sensor is characterized by comprising the following steps:
step 1, performing SiC deep cavity etching on the middle part of the C surface of a SiC bottom layer through femtosecond laser to form a SiC film with a cavity, so that an MEMS cantilever beam can be conveniently manufactured in the later stage;
step 2, manufacturing a first mask for preparing the piezoresistor strips on the Si surface of the SiC bottom layer, carrying out light doping or medium doping on the SiC bottom layer of a first mask pattern region by adopting an ion implantation process, and removing the first mask to form four piezoresistor strips;
step 3, manufacturing a second mask for preparing an electrode and a connecting circuit on the Si surface of the SiC bottom layer, heavily doping the SiC bottom layer of the second mask pattern region by adopting an ion implantation process, removing the second mask, forming the electrode and the connecting circuit, and completing the preparation of the Wheatstone bridge detection circuit on the SiC bottom layer;
step 4, manufacturing a third mask for preparing a metal bonding pad on the Si surface of the SiC bottom layer, depositing conductive metal in the pattern area of the third mask and the third mask through an evaporation coating or sputtering coating process, removing the third mask, and forming the metal bonding pad, wherein the metal bonding pad is positioned right above the corresponding electrode;
step 5, manufacturing a mask IV on the metal bonding pad in the step 4, and depositing SiO in the pattern area of the mask IV and the mask IV2Removing the mask to form SiO deposited on the SiC bottom layer2A layer;
step 6, in SiO2Preparing a mask five on the layer, and depositing Si in the pattern areas of the mask five and the mask five3N4Removing the mask five to form a film deposited on SiO2Si on the layer3N4Layer, by controlling the shape of mask five, so that Si3N4Layer area less than SiO2Layer so that the metal pad is exposed to the outside.
Step 7, in SiO2Preparing a mask six on the layer, depositing a conductive metal film in the pattern area of the mask six and the mask six, and removing the mask six to form an area and Si3N4A top metal layer of the same size;
step 8, performing graphical etching on the cavity bottom area of the SiC bottom layer through femtosecond laser to form a cantilever beam structure on the SiC bottom layer;
step 9, preparing a mask seven with a shape corresponding to the graph etched on the SiC bottom layer in the step 8 on the upper surface of the top metal layer, sequentially penetrating the top metal layer, the graph of the composite silicon compound middle layer and the graph of the SiC bottom layer by adopting wet etching to form a cantilever beam structure, and then removing the mask seven to prepare a SiC temperature sensor blank;
and step 10, carrying out high-temperature annealing on the SiC temperature sensor blank to form ohmic contact between the metal layer at the bottom of the bonding pad and the electrode, and finishing the manufacturing of the SiC temperature sensor with the cantilever beam structure.
Further, before the deep cavity etching in the step 1, the C surface of the SiC bottom layer is thinned according to the measuring range of the prepared SiC temperature sensor.
Furthermore, in the step 8, the patterned etching is performed in an internal region surrounded by the wheatstone bridge detection circuit, and the etched pattern is in a shape of a Chinese character 'wang'.
The working principle of the SiC temperature sensor with the cantilever beam structure is as follows: because the thermal expansion coefficients of the SiC bottom layer, the composite silicon compound middle layer and the top metal layer are different and have larger difference, when the temperature of the MEMS cantilever beam is changed due to the change of the external environment temperature, thermal stress can be generated among all layers of structures in the MEMS cantilever beam. Under the action of thermal stress, the MEMS cantilever beam can deform and bend upwards or downwards, and the piezoresistor strips in the SiC bottom layer can also bend upwards or downwards along with the deformation. The bending degree of the MEMS cantilever beam can be increased or decreased along with the increase or decrease of the external environment temperature, and the bending degree of the piezoresistor strip can be increased or decreased along with the increase or decrease of the external environment temperature. Because the existence of the piezoresistive effect of the SiC semiconductor material, the resistivity of the piezoresistor strip can be changed, the change of the resistivity of the piezoresistor strip is in positive correlation with the bending degree of the MEMS cantilever beam, and because the deformation degrees of the longitudinal piezoresistor strip and the transverse piezoresistor strip during working are different, the resistivity change is also different, the balance of the Wheatstone bridge is broken, and therefore, the Wheatstone bridge detection circuit can successfully convert the resistance change in the circuit into the change of current or voltage value and output the change outwards. According to the principle, the temperature signal of the environment can be converted into the electric signal by using the sensor, and the temperature value and the electric signal value can form a one-to-one corresponding functional relation after data processing, so that the temperature measurement is realized.
Advantageous effects
1. Compared with the existing Si-based integrated sensor, the technical scheme of the invention selects SiC as the sensor substrate material, and has higher reliability, longer service life, more stable sensitivity, better linearity and shorter response time when working in a severe environment, especially a high-temperature and strong-corrosivity environment.
2. Compared with the existing Si-based piezoresistive temperature sensor, the technical scheme of the invention adopts the ion implantation process to form the electric connection circuit in the SiC bottom layer, thereby avoiding the traditional Si-based piezoresistive sensor adopting a mode of connecting four piezoresistor strips by leads to form a Wheatstone bridge, not only reducing the probability of sensor failure caused by the connection failure of the leads, but also reducing the loss of signals in the Wheatstone bridge and improving the sensitivity of the sensor.
3. Compared with the existing Si-based piezoresistive temperature sensor, the technical scheme of the invention innovatively adds the composite silicon compound middle layer which has the function of thermal shock resistance to protect the SiC bottom layer, and simultaneously, the composite silicon compound middle layer is used as an insulating layer to separate the top metal layer from a Wheatstone bridge detection circuit on the SiC bottom layer to protect the circuit.
Drawings
Fig. 1 is a schematic three-dimensional structure diagram of a cantilever-structured SiC temperature sensor according to an embodiment of the present invention.
Fig. 2 is a cross-sectional view of a SiC temperature sensor of a cantilever structure according to an embodiment of the present invention.
Fig. 3 is a schematic diagram of a structure of a mask after a mask pattern is formed in step 3 according to the embodiment of the present invention.
FIG. 4 is a schematic structural diagram of the piezoresistive region formed in step 3 and the mask removed.
Fig. 5 is a schematic structural diagram of a second mask after a mask pattern is manufactured in step 4 according to the embodiment of the present invention.
FIG. 6 is a schematic structural diagram illustrating the structure of the second mask after forming the electrical connection line region and removing the second mask in step 4 according to the embodiment of the present invention.
Fig. 7 is a schematic structural diagram of a mask after a mask three for making a mask pattern in step 5 of the embodiment of the present invention.
Fig. 8 is a schematic structural diagram of a metal pad deposited and a mask removed in step 6 according to the embodiment of the present invention.
Fig. 9 is a structural diagram illustrating a mask four after a mask pattern is fabricated in step 7 according to the embodiment of the present invention.
FIG. 10 shows SiO deposition in step 8 of an embodiment of the present invention2And (5) removing the mask to obtain a structural schematic diagram.
Fig. 11 is a schematic structural diagram of a mask after fifth mask patterns are formed in step 9 according to the embodiment of the present invention.
FIG. 12 illustrates Si deposition in step 10 according to an embodiment of the present invention3N4And (5) removing the mask five, and then, schematically representing the structure.
Fig. 13 is a structural diagram illustrating a mask six after a mask pattern is formed in step 11 according to the embodiment of the present invention.
Fig. 14 is a schematic structural diagram of a sixth step 12 of depositing a top metal layer and removing a mask according to the embodiment of the present invention.
Fig. 15 is a schematic structural diagram of a seventh mask after a mask pattern is formed in step 14 according to the embodiment of the present invention.
Fig. 16 is a partial cross-sectional view of a SiC temperature sensor of the cantilever beam structure of the present invention.
1-MEMS cantilever beam, 2-Wheatstone bridge detection circuit, 21-piezoresistive region, 211-longitudinal piezoresistor strip, 212-transverse piezoresistor strip, 22-electrical connection circuit region, 221-electrode, 222-connection circuit, 3-metal pad, 31-pad bottom metal layer, 32-pad top metal layer, 4-SiC bottom layer, 41-undoped region, 5-composite silicon compound intermediate layer, 51-SiO2Layer, 52-Si3N4Layer, 6-top metal layer, 71-mask one, 72-mask two, 73-mask three, 74-mask four, 75-mask five, 76-mask six, 77-mask seven.
Detailed Description
The following explains the embodiments of the cantilever structure SiC temperature sensor and the manufacturing method thereof in further detail with reference to the drawings.
The invention provides a SiC temperature sensor with a cantilever beam structure, which comprises an MEMS cantilever beam 1, a Wheatstone bridge detection circuit 2 and a metal bonding pad 3, wherein the MEMS cantilever beam 1 with a multilayer structure has three layers from bottom to top, namely a SiC bottom layer 4, a composite silicon compound middle layer 5 and a composite silicon compound middle layer 3A top metal layer 6; the SiC bottom layer 4 comprises three parts: piezoresistive region 21, electrical connection line region 22, and undoped region 41; the piezoresistive regions 21 are four piezoresistor strips in the wheatstone bridge detection circuit 2, and include a pair of longitudinal piezoresistor strips 211 and a pair of transverse piezoresistor strips 212, the electrical connection circuit region 22 is an electrical circuit for realizing interconnection of the piezoresistor strips in the wheatstone bridge detection circuit 2, and the undoped region 41 is an undoped SiC bottom layer 4, and plays roles of insulation and protection of the wheatstone bridge detection circuit 2; the composite silicon compound interlayer 5 is a composite interlayer formed by stacking a plurality of thin layers of silicon compounds, and SiO is adopted in the embodiment2With Si3N4The thicknesses of the silicon compound composite layers stacked from bottom to top are 0.3 +/-0.05 mu m and 0.2 +/-0.02 mu m respectively. SiO 22The layer 51 thermally expands to generate a compressive stress, Si3N4Tensile stress is generated after the layer 52 is thermally expanded, so that the stress concentration phenomenon of the composite silicon compound intermediate layer 5 caused by temperature change in the use process can be relieved by adopting the two materials; the SiO2The side length of layer 51 is equal to the side length of SiC bottom layer 4, Si3N4The layer 52 has sides less than SiO2The side length of the layer 51 is 300 +/-10 mu m, and a size allowance is reserved for the metal bonding pad 3 so as to realize the connection of the metal bonding pad 3 and an external circuit structure, namely SiO2Four through hole structures are distributed on the layer 51 and used for depositing the metal bonding pad 3, the through holes are located right above the electrode 221, and the length of each through hole is slightly larger than the length of the side of the electrode 221 by 3-5 microns. The top metal layer 6 is a metal layer having characteristics of high thermal expansion coefficient, high elasticity, high extensibility, etc., in this embodiment, copper Cu is used, but silver Ag, gold Au, aluminum Al, etc. may be used. .
The wheatstone bridge detection circuit 2 is composed of a piezoresistive region 21 and an electric connection circuit region 22, the electric connection circuit region 22 comprises an electrode 221 and a connection circuit 222, the piezoresistive region 21 and the electrode 221 are interconnected through the connection circuit 222 to form the wheatstone bridge detection circuit 2, in the embodiment, any two adjacent piezoresistor strips are mutually vertical on an extension line, and the four piezoresistor strips are arranged in a unidirectional mode to form a radial shape; in this embodiment, the wheatstone bridge detection circuit 2 is formed by implanting phosphorus ions by ion implantation, the piezoresistive region 21 is formed by light doping or medium doping, and the electrical connection circuit 222 is formed by heavy doping.
The metal bonding pad 3 comprises a bonding pad bottom metal layer 31 and a bonding pad top metal layer 32, the bonding pad bottom metal layer 31 is arranged above the electrode 221 and forms ohmic contact with the electrode, the bonding pad top metal layer 32 is arranged above the bonding pad bottom metal layer 31 and forms electric contact with the bonding pad bottom metal layer, the bonding pad top metal layer 32 has high oxidation resistance, and the metal bonding pad 3 and an external circuit are connected through a lead structure to achieve electric signal output of the temperature sensor; in this embodiment, the bottom metal layer 31 of the pad uses nickel Ni, and the top metal layer 32 of the pad uses platinum Pt.
The manufacturing method of the cantilever beam structured SiC temperature sensor of the embodiment includes the following steps:
step 1, according to the measurement range requirement, thinning the C surface of the SiC bottom layer 4 through grinding and polishing processes, and thinning the SiC bottom layer 4 to the thickness of the required measurement range.
And 2, performing SiC deep cavity etching on the C surface of the SiC bottom layer 4 by femtosecond laser on the basis of the step 1 to form a SiC film with a cavity, so that the MEMS cantilever beam 1 can be conveniently manufactured in the later stage.
And 3, on the basis of the step 2, manufacturing a first mask 71 for preparing the piezoresistor strip on the Si surface of the SiC bottom layer 4, and controlling the shape and the size of the piezoresistor area 21 when the first mask 71 is used for ion implantation, wherein the shape of the first mask is shown in FIG. 3. The SiC substrate 4 in the pattern region of mask one 71 is lightly or undoped to form piezoresistive regions 21, and then mask one 71 is removed to form four piezoresistive strips, as shown in fig. 4.
And 4, on the basis of the step 3, manufacturing a second mask 72 for preparing the electric connection line region 22 on the Si surface of the SiC bottom layer 4, wherein the shape and the size of the electric connection line region 22 are controlled during ion implantation, and the shape of the second mask 72 is shown in FIG. 5. The SiC bottom layer 4 of the pattern region of mask two 72 is heavily doped to form the electrical connection line regions 22. The second 72 is then masked to form the electrical connection line regions 22, as shown in the structure of FIG. 6.
And 5, on the basis of the step 4, manufacturing a third mask 73 on the Si surface of the SiC bottom layer 4 for controlling the shape and the size of the metal bonding pad 3, wherein the shape of the third mask 73 is shown in FIG. 7.
And 6, on the basis of the step 5, depositing conductive metal for manufacturing the metal bonding pad 3 in the pattern area of the mask III 73 by an evaporation coating or sputtering coating process, preferably, the metal nickel Ni can be adopted as the material of the bonding pad bottom metal layer 31 and has the thickness of 0.25 +/-0.02 mu m, and the metal platinum Pt can be adopted as the material of the bonding pad top metal layer 32 and has the thickness of 0.05 +/-0.01 mu m. Mask three 73 is then removed and metal pads 3 in electrical communication with electrodes 221 are formed on SiC underlayer 4, as in the structure shown in fig. 8.
Step 7, on the basis of the step 6, making a mask four 74 on the upper surface of the metal pad 3 for depositing SiO2Layer 51 and its shape and size are controlled, and mask four 74 is shaped as shown in fig. 9.
And 8, depositing SiO in the mask four 74 and the pattern area of the mask four 74 by a Chemical Vapor Deposition (CVD) process on the basis of the step 72Thin film, preferably, SiO2The film thickness is 0.3 +/-0.03 mu m. The mask four 74 is then removed, forming SiO deposited on the SiC bottom layer 42 Layer 51, as structured in fig. 10.
Step 9, on the basis of step 8, on SiO2The upper surface of layer 51 is masked five 75 for depositing Si3N4Layer 52 and its shape and size are controlled and mask five 75 is shaped as shown in fig. 11.
Step 10, on the basis of the step 9, depositing Si on the mask five 75 and the pattern area of the mask five 75 by a Chemical Vapor Deposition (CVD) process3N4Thin film, preferably, Si3N4The film thickness is 0.2 +/-0.02 mu m. Then removing the five 75 masks to form the deposit on the SiO2Si on layer 513N4Layer 52, as in the structure shown in fig. 12.
Step 11, on the basis of step 10, on SiO2A mask six 76 is formed on the top surface of layer 51 for depositing top metal layer 6 and controlling its shape and size, mask six 76 being shaped as shown in the structure of fig. 13.
And 12, depositing a metal film on the pattern areas of the mask six 76 and the mask six 76 by an evaporation coating or sputtering coating process on the basis of the step 11, wherein preferably, the metal film can be made of metal copper Cu and has the thickness of 0.3-5 microns. Mask six 76 is then removed to form a deposit on Si3N4 Top metal layer 6 on layer 52, as in the structure shown in fig. 14.
And 13, etching the C surface of the film of the SiC bottom layer 4 by femtosecond laser on the basis of the step 12, and engraving a Chinese character 'Wang' pattern region to form a cantilever beam structure on the SiC bottom layer 4.
Step 14, on the basis of the step 13, manufacturing a mask seven 77 which is the same as the Wang character pattern of the SiC bottom layer 4 on the upper surface of the top metal layer 6 and is used for forming a cantilever beam structure in a patterning mode and controlling the shape and the size of the cantilever beam structure, wherein the shape of the mask seven 77 is the structure shown in FIG. 15; and (3) patterning the top metal layer 6 and the composite silicon compound intermediate layer 5 by adopting wet etching to sequentially penetrate through the Wang-shaped pattern of the SiC bottom layer 4 to form a cantilever beam structure, and then removing a mask seven 77 to prepare a SiC temperature sensor blank with the shape of the structure shown in figure 1.
And 15, performing high-temperature annealing on the SiC temperature sensor blank on the basis of the step 14 to form ohmic contact between the metal layer 31 at the bottom of the bonding pad and the electrode 221, and thus finishing the manufacturing of the SiC temperature sensor with the cantilever beam structure.
It should be noted that, in the embodiment of the present invention, the pattern etched to form the cantilever structure is not limited to the shape of a wane, and may be any other shape as long as the cantilever is formed in the area of the wheatstone bridge detection circuit 2 on the SiC bottom layer 4, and the shape of the wane provided in the embodiment of the present invention is only an optimal embodiment for matching the shape of the wheatstone bridge detection circuit 2 in the embodiment, and does not represent a limitation on the shape of the cantilever pattern.
It should be further noted that, in the present invention, the wheatstone bridge detection circuit 2 is formed by doping on the SiC bottom layer 4 by using an ion implantation process, and the implantation of phosphorus ions is provided in this embodiment, and is not limited to phosphorus ions in practice, and phosphorus ions are merely an example.
The above embodiments are merely illustrative of the technical solutions of the present invention. The cantilever structure SiC temperature sensor and the manufacturing method thereof according to the present invention are not limited to the description in the above embodiments, but are subject to the scope defined by the claims. Any modification or supplement or equivalent replacement made by a person skilled in the art on the basis of this embodiment is within the scope of the invention as claimed in the claims. In addition, all the details are not described in the prior art.

Claims (10)

1. The utility model provides a SiC temperature sensor of cantilever beam structure which characterized in that: the composite silicon compound detection circuit comprises a SiC bottom layer, a composite silicon compound middle layer and a top metal layer from bottom to top, wherein a Wheatstone bridge detection circuit is formed on a Si surface of the SiC bottom layer through ion implantation process doping, an undoped region is an insulation protection region, conductive metal electrically communicated with an electrode of the Wheatstone bridge detection circuit is deposited on the SiC bottom layer to form a metal pad, the composite silicon compound middle layer is used for buffering thermal stress, the composite silicon compound middle layer is formed by stacking a plurality of silicon compound thin layers with low thermal expansion coefficients, high dielectric constants, high insulativity and different direction stresses generated after thermal expansion, the metal pad is exposed by selecting the deposition area of the composite silicon compound middle layer, the top metal layer and the uppermost layer of the composite silicon compound middle layer are deposited on the composite silicon compound middle layer in the same area, and a cavity is etched in the middle part of a C surface of, and a pattern penetrating through the top metal layer is etched at the bottom of the cavity to form the MEMS cantilever beam structure.
2. The SiC temperature sensor of claim 1, wherein: the Wheatstone bridge detection circuit comprises four voltage-sensitive resistor strips, electrodes and a connecting circuit for connecting the four voltage-sensitive resistor strips and the electrodes, wherein the four voltage-sensitive resistor strips are a pair of longitudinal voltage-sensitive resistor strips and a pair of transverse voltage-sensitive resistor strips, the connecting circuit is used for connecting the four voltage-sensitive resistor strips end to end, and the four electrodes are distributed on the connecting circuit between the two adjacent voltage-sensitive resistor strips.
3. The SiC temperature sensor of claim 2, wherein: the four piezoresistor strips are prepared by lightly doping or medium doping the SiC bottom layer local area through an ion implantation process, the doping type is N type or P type, and the electrodes and the connecting circuit are prepared by heavily doping the SiC bottom layer local area through the ion implantation process with the piezoresistor strips in the same type.
4. The SiC temperature sensor of claim 2, wherein: any two adjacent piezoresistor strips are mutually vertical on the extension line, and the four piezoresistor strips are arranged in a unidirectional mode to form a radial shape.
5. The SiC temperature sensor of claim 2, wherein: the metal bonding pad comprises a bonding pad bottom metal layer and a bonding pad top metal layer, the bonding pad bottom metal layer is arranged above the electrode and forms ohmic contact with the electrode, the bonding pad top metal layer is arranged above the bonding pad bottom metal layer and forms electric contact with the bonding pad bottom metal layer, and the bonding pad top metal layer is connected with the metal bonding pad and an external circuit through a lead structure.
6. The SiC temperature sensor of claim 5, wherein: the metal layer at the bottom of the bonding pad is made of metal nickel, metal aluminum or titanium, and the metal layer at the top of the bonding pad is made of metal platinum with high oxidation resistance.
7. The SiC temperature sensor of claim 1, wherein: the composite silicon compound interlayer comprises SiO with opposite stress after thermal expansion2Layer and Si3N4Layer of said SiO2A layer deposited on the SiC bottom layer around the metal pad, the Si3N4Layer deposition on SiO2On the layer.
8. The SiC temperature sensor of claim 1, wherein: the top metal layer is made of a metal material with high thermal expansion coefficient, high elasticity and good ductility.
9. A preparation method of a cantilever beam structured SiC temperature sensor is characterized by comprising the following steps:
step 1, performing SiC deep cavity etching on the middle part of the C surface of a SiC bottom layer through femtosecond laser to form a SiC film with a cavity, so that an MEMS cantilever beam can be conveniently manufactured in the later stage;
step 2, manufacturing a first mask for preparing the piezoresistor strips on the Si surface of the SiC bottom layer, carrying out light doping or medium doping on the SiC bottom layer of a first mask pattern region by adopting an ion implantation process, and removing the first mask to form four piezoresistor strips;
step 3, manufacturing a second mask for preparing an electrode and a connecting circuit on the Si surface of the SiC bottom layer, heavily doping the SiC bottom layer of the second mask pattern region by adopting an ion implantation process, removing the second mask, forming the electrode and the connecting circuit, and completing the preparation of the Wheatstone bridge detection circuit on the SiC bottom layer;
step 4, manufacturing a third mask for preparing a metal bonding pad on the Si surface of the SiC bottom layer, depositing conductive metal in the pattern area of the third mask and the third mask through an evaporation coating or sputtering coating process, removing the third mask, and forming the metal bonding pad, wherein the metal bonding pad is positioned right above the corresponding electrode;
step 5, manufacturing a mask IV on the metal bonding pad in the step 4, and depositing SiO in the pattern area of the mask IV and the mask IV2Removing the mask to form SiO deposited on the SiC bottom layer2A layer;
step 6, in SiO2Preparing a mask five on the layer, and depositing Si in the pattern areas of the mask five and the mask five3N4Removing the mask five to form a film deposited on SiO2Si on the layer3N4Layer, by controlling the shape of mask five, so that Si3N4Layer area less than SiO2A layer so that the metal pad is exposed to the outside;
step 7, in SiO2Preparing a mask six on the layer, depositing a metal film in the pattern area of the mask six and the mask six, and removingRemoving the mask six, forming area and Si3N4A top metal layer of the same size;
step 8, performing graphical etching on the cavity bottom area of the SiC bottom layer through femtosecond laser to form a cantilever beam structure on the SiC bottom layer;
step 9, preparing a mask seven with a shape corresponding to the graph etched on the SiC bottom layer in the step 8 on the upper surface of the top metal layer, sequentially penetrating the top metal layer, the graph of the composite silicon compound middle layer and the graph of the SiC bottom layer by adopting wet etching to form a cantilever beam structure, and then removing the mask seven to prepare a SiC temperature sensor blank;
and step 10, carrying out high-temperature annealing on the SiC temperature sensor blank to form ohmic contact between the metal layer at the bottom of the bonding pad and the electrode, and finishing the manufacturing of the SiC temperature sensor with the cantilever beam structure.
10. The method for producing the SiC temperature sensor according to claim 8, characterized in that: before the deep cavity etching in the step 1, thinning the C surface of the SiC bottom layer according to the measuring range of the prepared SiC temperature sensor.
CN201910981318.5A 2019-10-16 2019-10-16 SiC temperature sensor with cantilever beam structure and manufacturing method thereof Active CN110745774B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910981318.5A CN110745774B (en) 2019-10-16 2019-10-16 SiC temperature sensor with cantilever beam structure and manufacturing method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910981318.5A CN110745774B (en) 2019-10-16 2019-10-16 SiC temperature sensor with cantilever beam structure and manufacturing method thereof

Publications (2)

Publication Number Publication Date
CN110745774A true CN110745774A (en) 2020-02-04
CN110745774B CN110745774B (en) 2022-12-16

Family

ID=69278401

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910981318.5A Active CN110745774B (en) 2019-10-16 2019-10-16 SiC temperature sensor with cantilever beam structure and manufacturing method thereof

Country Status (1)

Country Link
CN (1) CN110745774B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111825056A (en) * 2020-07-17 2020-10-27 杭州电子科技大学 Method for forming cantilever probe based on femtosecond laser and high temperature and cantilever probe
CN112710405A (en) * 2020-12-08 2021-04-27 北京智芯微电子科技有限公司 Temperature sensor
CN112817142A (en) * 2020-12-31 2021-05-18 歌尔股份有限公司 MEMS scanning mirror
CN113671690A (en) * 2020-05-13 2021-11-19 安徽中科米微电子技术有限公司 Rotating shaft structure and MEMS double-shaft rotating mirror

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5165283A (en) * 1991-05-02 1992-11-24 Kulite Semiconductor Products, Inc. High temperature transducers and methods of fabricating the same employing silicon carbide
CN103033276A (en) * 2012-12-27 2013-04-10 长安大学 Silicon carbide (SIC) temperature sensor and manufacturing method thereof
CN104330195A (en) * 2014-10-16 2015-02-04 上海师范大学 High temperature pressure sensor technology based on heavy doping 4H-SiC substrate
CN104614086A (en) * 2015-03-06 2015-05-13 上海新微技术研发中心有限公司 Air pressure type temperature sensor and manufacturing method thereof
CN107827077A (en) * 2017-09-21 2018-03-23 广东电网有限责任公司惠州供电局 A kind of pressure resistance type MEMS temperature sensor and preparation method thereof
CN107957299A (en) * 2017-11-27 2018-04-24 电子科技大学 A kind of carborundum linear temperature sensor and its temp measuring method and manufacture method
CN109724721A (en) * 2019-01-21 2019-05-07 武汉大学 The SiC high-temp pressure sensor and its manufacturing method of non-leaded package
US20190257703A1 (en) * 2018-02-19 2019-08-22 Stmicroelectronics S.R.L. Strain gauge with mechanically decoupled temperature sensor

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5165283A (en) * 1991-05-02 1992-11-24 Kulite Semiconductor Products, Inc. High temperature transducers and methods of fabricating the same employing silicon carbide
CN103033276A (en) * 2012-12-27 2013-04-10 长安大学 Silicon carbide (SIC) temperature sensor and manufacturing method thereof
CN104330195A (en) * 2014-10-16 2015-02-04 上海师范大学 High temperature pressure sensor technology based on heavy doping 4H-SiC substrate
CN104614086A (en) * 2015-03-06 2015-05-13 上海新微技术研发中心有限公司 Air pressure type temperature sensor and manufacturing method thereof
CN107827077A (en) * 2017-09-21 2018-03-23 广东电网有限责任公司惠州供电局 A kind of pressure resistance type MEMS temperature sensor and preparation method thereof
CN107957299A (en) * 2017-11-27 2018-04-24 电子科技大学 A kind of carborundum linear temperature sensor and its temp measuring method and manufacture method
US20190257703A1 (en) * 2018-02-19 2019-08-22 Stmicroelectronics S.R.L. Strain gauge with mechanically decoupled temperature sensor
CN109724721A (en) * 2019-01-21 2019-05-07 武汉大学 The SiC high-temp pressure sensor and its manufacturing method of non-leaded package

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
刘庆海等: "表面微机械MEMS温度传感器研究", 《传感技术学报》 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113671690A (en) * 2020-05-13 2021-11-19 安徽中科米微电子技术有限公司 Rotating shaft structure and MEMS double-shaft rotating mirror
CN111825056A (en) * 2020-07-17 2020-10-27 杭州电子科技大学 Method for forming cantilever probe based on femtosecond laser and high temperature and cantilever probe
CN112710405A (en) * 2020-12-08 2021-04-27 北京智芯微电子科技有限公司 Temperature sensor
CN112710405B (en) * 2020-12-08 2023-04-28 北京智芯微电子科技有限公司 Temperature sensor
CN112817142A (en) * 2020-12-31 2021-05-18 歌尔股份有限公司 MEMS scanning mirror

Also Published As

Publication number Publication date
CN110745774B (en) 2022-12-16

Similar Documents

Publication Publication Date Title
CN110745774B (en) SiC temperature sensor with cantilever beam structure and manufacturing method thereof
KR100812996B1 (en) Micro gas sensor and method for manufacturing the same
US4426768A (en) Ultra-thin microelectronic pressure sensors
US4463336A (en) Ultra-thin microelectronic pressure sensors
US20060291674A1 (en) Method of making silicon-based miniaturized microphones
CN112362203A (en) High-temperature pressure sensor chip suitable for various packaging modes and manufacturing method
US11686637B2 (en) Silicon carbide-based combined temperature-pressure micro-electro-mechanical system (MEMS) sensor chip and preparation method thereof
CN111707404B (en) High-temperature-resistant silicon carbide pressure sensor and preparation method thereof
CN110015632A (en) Senser element and its manufacturing method
CN109342836B (en) Production process based on piezoelectric piezoresistive broadband high-field-intensity miniature electric field sensor
CN115557463B (en) Pressure sensor chip, preparation method thereof and pressure sensor
CN116026501B (en) Pressure sensor and manufacturing method thereof
CN114729840A (en) Sensor element and method for producing a sensor element
CN206828092U (en) A kind of pressure sensor for micro electro-mechanical system chip of Liang Mo mechanisms
CN114684774A (en) Silicon piezoresistive pressure sensor chip and preparation method thereof
CN213812675U (en) High-temperature pressure sensor chip for realizing leadless package
CN114061797A (en) MEMS piezoresistive pressure sensor with double bridge structures and preparation method thereof
US20080265168A1 (en) Radiation sensor element, method for producing a radiation sensor element and sensor field
CN112357877A (en) MEMS SOI pressure sensor and preparation method thereof
CN112479151A (en) Manufacturing method of multi-sensor layer, multi-sensor chip and manufacturing method thereof
CN111879447A (en) Differential SiC capacitance pressure sensor with concentric ring structure and preparation method thereof
CN213364087U (en) Capacitive MEMS pressure sensor applied to electronic terminal product
CN112924058A (en) Pressure sensor and method for manufacturing the same
CN112033583A (en) SiC capacitance pressure sensor with surface array boss structure and preparation method
CN114485797B (en) Temperature and pressure integrated MEMS sensor chip and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant