CN110531114A - A kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation and preparation method thereof - Google Patents
A kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation and preparation method thereof Download PDFInfo
- Publication number
- CN110531114A CN110531114A CN201910683519.7A CN201910683519A CN110531114A CN 110531114 A CN110531114 A CN 110531114A CN 201910683519 A CN201910683519 A CN 201910683519A CN 110531114 A CN110531114 A CN 110531114A
- Authority
- CN
- China
- Prior art keywords
- mass block
- measuring unit
- sensitive
- chip
- mems
- 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
Links
Classifications
-
- 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
- B81C1/00142—Bridges
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P15/12—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by alteration of electrical resistance
-
- 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
- B81B2201/0228—Inertial sensors
- B81B2201/0235—Accelerometers
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Pressure Sensors (AREA)
Abstract
The invention discloses MEMS three-axis piezoresistance formula accelerometer chips of a kind of purely axial deformation and preparation method thereof, X measuring unit, Y measuring unit and Z measuring unit in the sensor are respectively used to the acceleration of measurement X-direction, Y-direction and Z-direction, realize the separating and measuring of three directional accelerations；Each measuring unit includes mass block, supporting beam and sensitive beam, either which measuring unit, it is separately positioned that supporting beam and sensitive beam pass through mass block, supporting beam supports mass block movement, and stress focuses primarily upon sensitive beam, so that the varistor resistance value in sensitive beam changes, Each performs its own functions for the two, greatly weakens the direct-coupling relationship between sensitivity and resonance frequency；Simultaneously because two mass blocks move synchronously, the sensitive beam both ends being secured to also move synchronously, so that sensitive beam meets purely axial deformation condition always, under identical resonance frequency, the sensitivity of sensor is optimal, so that sensor chip index with good performance.
Description
[technical field]
The invention belongs to micro-mechanical electronic system sensor element fields, and in particular to a kind of MEMS tri- of purely axial deformation
Axis piezoresistive accelerometer chip and preparation method thereof.
[background technique]
The yield of MEMS acceleration transducer is the mechanical meaurement sensor for being only second to pressure sensor, be current application than
One of more MEMS device.MEMS piezoresistive acceleration sensor structure is simple, low-profile, and superior performance is especially suitable
The measurement of low frequency acceleration.It in terms of space flight in addition to being used for a variety of overloads such as aircraft wind tunnel test and flight test and vibration
Outside parameter measurement, it can be used for the test of each stage vibration parameters of engine testsand in industrial aspect.
There are many measuring principles used by MEMS acceleration transducer, mainly there is pressure resistance type, piezoelectric type, condenser type, heat
Convection type, tunnel type, optical fiber type and resonant mode.Compared with other kinds of MEMS acceleration transducer, MEMS piezoresistive adds
For velocity sensor because its measurement range is wide, processing technology is simple, can measure dynamic and stationary singnal, dynamic response is good, test side
Just, the advantages that subsequent process circuit is simple, low in cost and be widely used.
For three-axis piezoresistance formula acceleration transducer, for measuring the acceleration in three directions, no matter for which direction
For, the sensitivity of acceleration transducer and bandwidth of operation are its main working index always, therefore in the design process often
Carry out design acceleration sensor structure for the two parameters as optimization aim.And exist between intrinsic frequency and sensitivity mutual
Restricting relation, to affect further increasing for acceleration transducer.In the design of acceleration transducer, acceleration is weakened
The mutual restricting relation of transducer sensitivity and intrinsic frequency, while the optimal value for obtaining sensitivity and intrinsic frequency is very heavy
It wants.For acceleration transducer when measuring the acceleration in the direction z, since acceleration is perpendicular to chip, so that adjusting the measurement
The sensitivity of unit and intrinsic frequency are particularly important.
[summary of the invention]
It is an object of the invention to overcome the above-mentioned prior art, a kind of tri- axis pressure of MEMS of purely axial deformation is provided
Resistance accelerometer chip and preparation method thereof；It is separately positioned that the wafer support beam and sensitive beam pass through mass block, greatly
The direct-coupling relationship between sensitivity and resonance frequency is weakened, under identical resonance frequency, the sensitivity of sensor reaches
It is optimal, so that sensor chip index with good performance.
In order to achieve the above objectives, the present invention is achieved by the following scheme:
A kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation, comprising: be fixed in chip outline border
X measuring unit, Y measuring unit and Z measuring unit, three measuring units are isolated by chip outline border；Z measuring unit it is vertical
Centerline parallel is in the vertical centerline of X measuring unit, and the vertical centerline of Y measuring unit is perpendicular to the vertical of Z measuring unit
Center line；The chip outline border is bonded on bottom glass plate；Z measuring unit includes third mass block and the 4th mass block, and
The outer side edges of three mass blocks and the 4th mass block pass through second supporting beam and connect with chip outline border；Third mass block it is interior
The first protrusion is provided on side, the two sides of the first protrusion are respectively arranged with first groove；The inner side edge of 4th mass block
On be provided with the second groove, the two sides of the second groove are respectively arranged with one second protrusion；First protrusion is engaged on the second groove
In, each second protrusion is engaged in second groove；Each second project through third sensitive beam and first protrusion
Connection；Two outer ends of third mass block and the 4th mass block inner side edge pass through the second sensitive beam connection respectively；
Second sensitive beam connects to form favour stone full-bridge by metal lead wire with the varistor in third sensitive beam.
A further improvement of the present invention is that:
Preferably, the plane of second supporting beam is parallel to X/Y plane, and the plane of the second supporting beam is arranged in third matter
The centerline in gauge block or the 4th direction mass block z；Snakelike beam is fixedly installed in second supporting beam.
Preferably, the snakelike beam includes several serpentine sectors；Each serpentine sector is fixed at third quality
Between block and chip outline border, or it is fixed between the 4th mass block and chip outline border；The serpentine sector includes mutual
Vertical the first plane and the second plane, the first plane are parallel to the cross central line of Z measuring unit, and the second plane is parallel to Z
The vertical centerline of measuring unit, the both ends of each the first plane are connected separately with second plane.
Preferably, first protrusion includes the first linkage section and the first protruding end of integrally connected, and the first linkage section will
Third quality block main body and the first protruding end integrally connected, the width of the first protruding end are greater than the width of the first linkage section；Second
Protrusion includes the second linkage section and the second protruding end, and the second linkage section connects the 4th mass block main body with the second protruding end, the
The width of two protruding ends is greater than the width of the second linkage section；Each second protruding end is convex by a third sensitive beam and first
Outlet connection.
Preferably, two the second sensitive beams are separately positioned on the outside of second linkage section.
Preferably, X measuring unit is identical with the structure of Y measuring unit, two the first measuring block compositions of each freedom, each
It include the first mass block and the second mass block in first measuring block, the outer side edges of the first mass block and the second mass block pass through one
A first supporting beam is connected with chip outline border, and the inner side edge of the first mass block and the second mass block is sensitive by hinge beam and first
Beam connection；
The varistor in the first sensitive beam in X measuring unit connects to form favour stone half-bridge by metal lead wire；Y is surveyed
The varistor in the first sensitive beam in amount unit connects to form favour stone half-bridge by metal lead wire.
Preferably, the inner side edge of the first mass block and the second mass block is provided with the first gap, two the first gap phases
The cross central line of first measuring block is symmetrical arranged；Inner face of the both ends of hinge beam respectively with two the first gap is fixed
Connection；Hinge beam is arranged in the vertical centerline of the first measuring block.
Preferably, the inner side edge of the first mass block and the second mass block is connected by two the first sensitive beams, and two first
Sensitive beam is separately positioned on the two sides of the first gap, and two the first sensitive beams are symmetrical relative to hinge beam.
Preferably, the second gap is provided on the outside of the first mass block and the second mass block；Each first supporting beam
One end be fixedly connected with chip outline border, the inner face of the other end and the second gap is fixedly connected；The setting of first supporting beam is the
In the vertical centerline of one measuring block.
A kind of preparation method of the MEMS three-axis piezoresistance formula accelerometer chip of above-mentioned purely axial deformation, including following step
It is rapid:
1) two-sided thermal oxide is carried out to soi wafer, is respectively formed one layer of hot oxygen two in the upper and lower surfaces of soi wafer
The hot oxygen silicon dioxide layer of the hot oxygen silicon dioxide layer of silicon oxide layer, respectively upper surface and lower surface；
2) it using version is lightly doped, is removed in the lightly doped region of the upper surface SOI by photoetching and reaction ionic etching method
The hot oxygen silicon dioxide layer in upper surface, in lightly doped region adulterate boron ion after, formed lightly doped district；
3) heavy doping version is utilized, the hot oxygen in upper surface in heavily doped region is removed by photoetching and reaction ionic etching method
Silicon dioxide layer carries out heavy doping in heavily doped region, forms ohmic contact regions；
4) in soi wafer front by physical vapor deposition method depositing Ti/Al layers, by metal pad and conducting wire version into
Row photoetching forms metal lead wire and pad structure；
5) layer of silicon dioxide layer, lower surface are deposited by vapour deposition process at the back side of the hot oxygen silicon dioxide layer in lower surface
Hot oxygen silicon dioxide layer and silicon dioxide layer form double mask layers；
6) double mask layers in the deep etching region of the soi wafer back side are removed by reaction ionic etching method, so that SOI silicon
Substrate silicon in piece deep etching region is exposed；By deep reaction ion etching method etched substrate silicon, etch away X measuring unit and
The one of a part and the first mass block of first supporting beam and hinge beam lower part and the second mass block lower part in Y measuring unit
Part；
7) double mask layers of the second supporting beam and snakelike beam back-etching region in Z measuring unit are removed by photoetching；It is logical
Too deep reactive ion etching method continues to etch, and forms the lower part of the second supporting beam, the lower part of snakelike beam, the first supporting beam
Lower part, the lower part of hinge beam and the base infrastructure of all mass blocks；
8) by movement clearance domain, photoresist exposure mask is carried out to bottom glass plate, wet etching, In are carried out by KOH
Empty slot region is formed on bottom glass plate；
9) it is performed etching by deep reaction ion etching method double mask layers remaining to the soi wafer back side, so that SOI silicon
The substrate silicon of piece is exposed；Substrate silicon area is encapsulated on bottom glass plate by anode linkage；
10) the hot oxygen silicon dioxide layer in upper surface that removal soi wafer is etched by reaction ionic etching method, coats one layer
Photoresist, then by inductively coupled plasma etching method be etched to buried oxide layer stop, formed the first supporting beam, hinge beam,
The upper part of sensitive beam and all mass blocks forms the device layer portions of the second supporting beam and snakelike beam.
11) device layer and buried oxide layer that the second upper surface of support beam is removed by reaction ionic etching method, then pass through
Reaction deep ion lithographic method etches away the device layer and buried oxide layer of snakelike beam upper area, the second supporting beam and snakelike beam it is upper
Partial etching is completed；
12) the soi wafer front for having etched completion spraying photoresist is protected, removes the light in corresponding buried oxide layer region
Photoresist, then using the remaining buried oxide layer in buffer etching soi wafer front, naturally dry after cleaning soi wafer is positive, finally
The positive photoresist of soi wafer is removed again；
13) soi wafer, the MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation are handled using low temperature annealing process
It completes.
Compared with prior art, the invention has the following advantages:
X the invention discloses a kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation, in the sensor
Measuring unit, Y measuring unit and Z measuring unit are respectively used to the acceleration of measurement X-direction, Y-direction and Z-direction, it can be achieved that three
The separating and measuring of a directional acceleration；Z unit includes mass block, supporting beam and sensitive beam；Supporting beam and sensitive beam pass through quality
Block is separately positioned, and supporting beam supports mass block movement, and stress focuses primarily upon sensitive beam, so that the varistor in sensitive beam
Resistance value changes, and Each performs its own functions for the two, greatly weakens the direct-coupling relationship between sensitivity and resonance frequency；Together
When moving synchronously due to two mass blocks, the sensitive beam both ends being secured to also move synchronously, thus sensitive beam meet always it is pure
Axial deformation condition, under identical resonance frequency, the sensitivity of sensor is optimal, so that the sensor chip has well
Performance indicator；The inner connection parts of third mass block and the 4th mass block are set as matching the structure of engagement, increase by two
The fastness connected between person；Second sensitive beam and third sensitive beam are because one is to be directly connected to third mass block and the 4th matter
The inner side edge of gauge block, the other is the telescoping part of connection, when so that chip is by acceleration in Z-direction, the second sensitive beam
It is to be stretched power with third sensitive beam one, one is made with this configuration by compressing force, and then composition favour stone full-bridge
In a structure i.e. constitute favour stone full-bridge, that is, simplify structure, and improve output sensitivity, sensitivity compared to
Traditional half bridge designs are doubled；The separating and measuring of 100g or less 3-axis acceleration may be implemented in the sensor chip.
Further, the centerline of third mass block or the 4th direction mass block z is set in the second supporting beam, so that
The attachment force of beam can be uniformly supported between third mass block or the 4th mass block and chip outline border；In second supporting beam
It is provided with snakelike beam, snakelike beam is detour type structure, and snakelike beam extraction wire and can not increase supporting beam rigidity；When chip by
To the direction z acceleration when, distinctive detour type mass end structure can reduce Z measuring unit by the direction z accelerate
When spending, chip outline border is reduced to the restraint of third mass block or the 4th mass block, while snakelike beam is arranged in supporting beam, again
It ensure that mass block and chip outline border can be connected securely, while not only to exist in Z measuring unit and stretching sensitive beam, but also depositing
In the function of compression sensitive beam, and then form favour stone full-bridge, Lai Tigao output sensitivity；Snakelike beam is arranged in supporting beam,
It in turn ensures that mass block and chip outline border can be connected securely, and then is sensed in sensitivity, the reduction for improving acceleration transducer
While the cross sensitivity of device, the attachment force of mass block and chip outline border ensure that；Snakelike beam is provided with multiple serpentine sectors,
It can guarantee that metal lead wire can be uniformly distributed to be brought out.
Further, make it possible to be formed chimeric by the way that linkage section and protruding end of different size is arranged in Z measuring unit
Structure.
Further, two the second sensitive beams are positioned close to the position of edge, improve its sensitivity.
Further, in X measuring unit and Y measuring unit, it is separately positioned that supporting beam and sensitive beam pass through mass block, branch
Beam support mass block movement is supportted, and stress focuses primarily upon sensitive beam, so that the varistor resistance value in sensitive beam becomes
Change, Each performs its own functions for the two, greatly weakens the direct-coupling relationship between sensitivity and resonance frequency；Simultaneously because two mass
Block moves synchronously, and the sensitive beam both ends being secured to also move synchronously, so that sensitive beam meets purely axial deformation condition always.
Further, X measuring unit or Y measuring unit, hinge beam are arranged on the center line of each measuring block,
First sensitive beam is symmetrical relative to hinge beam；When receiving the acceleration in the direction x or the direction y, since two mass blocks are being added
Speed can move synchronously when acting on, so that the movement of the sensitive beam both ends being secured at any time is identical, sensitive beam both ends
Axial displacement on the contrary, and lateral displacement is offset, and since sensitive beam is sufficiently fine, mass block bending in both ends is small to the moment of flexure of sensitive beam
To can ignore, so that sensitive beam meets the condition of purely axial deformation always, by the strain energy concentration of sensitive beam in axial deformation,
Considerably increase the sensitivity of sensor.
Further, the gap structure on mass block can increase between mass block or between mass block and chip outline border
Distance, extend the length of hinge beam or supporting beam, enhance between mass block or the attachment force between mass block and chip outline border.
The invention also discloses a kind of preparation methods of the MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation, should
Preparation method, this method divide multistep for the structure of the MEMS three-axis piezoresistance formula accelerometer chip of distinctive purely axial deformation
The methods of reaction ionic etching method, the vapour deposition process of plasma enhanced chemical, deep reaction ion etching method are used
Prepare chip；Since Z unit supporting beam is in, chip thickness direction (direction) is intermediate, has very for the processing of MEMS technology
Big challenge, the present invention is using the double mask layers in the back side, and deep reaction ion etching, etches the different ditch of back side depth in two steps
Slot makes the lower half portion structure of Z supporting beam and mass block, supporting beam, the lower half portion structure of hinge beam while shaping, while just
Face elder generation etched features layer, then buried oxide layer is etched, the basal layer on Z axis supporting beam top is finally etched, the whole knot of supporting beam is formed
Structure.
[Detailed description of the invention]
Fig. 1 is overall structure diagram of the invention；
Fig. 2 is the part A enlarged diagram in Fig. 1；
Fig. 3 is the part B enlarged diagram in Fig. 1；
Fig. 4 is the C portion enlarged diagram in Fig. 1；
Fig. 5 is the working principle diagram of sensor x, y direction measuring unit；
Fig. 6 is the working principle diagram of sensor z direction measuring unit；
Fig. 7 is the preparation structure schematic diagram of sensor chip；
Wherein, (a) figure is step 1)；(b) figure is step 2)；(c) figure is step 3)；(d) figure is step 4)；(e)
Figure is step 5)；(f) figure is step 6)；(g) figure is step 7)；(h) figure is step 8)；(i) figure is step 9)；
(j) figure is step 10)；(k) figure is step 11)；(l) figure is step 12)；
Fig. 8 is the preparation structure flow chart of sensor chip；
Wherein: the first supporting beam of 1-；The first measuring block of 2-；3- hinge beam；4- sensitive beam；5- chip outline border；6- second is surveyed
Gauge block；The snakelike beam of 7-；The second supporting beam of 8-；The hot oxygen silicon dioxide layer of 9-；10- buried oxide layer；11- device layer；12- substrate silicon；13-
Lightly doped district；14- photoresist；The ohmic contact regions 15-；16- metal lead wire；17- pad structure；18- silicon dioxide layer；The bottom 19-
Layer glass plate；20-Cu/Ar layers；21- empty slot region；The first mass block of 2-1-；The second mass block of 2-2；The first gap of 2-3-；2-
The second gap of 4-；The first sensitive beam of 4-1-；The second sensitive beam of 4-2；4-3 third sensitive beam；6-1- third mass block；6-2 the 4th
Mass block；The first protrusion of 6-3-；The first groove of 6-4-；The second protrusion of 6-5-；The second groove of 6-6-；The first linkage section of 6-3-1-；
The first protruding end 6-3-2-；The second linkage section of 6-5-1-；The second protruding end 6-5-2-；The front end 6-6-1- groove；The rear end 6-6-2-
Groove；7-1- serpentine sector；The first plane of 7-2-；The second plane of 7-3-；The hot oxygen silicon dioxide layer in the upper surface 9-1-；9-2- following table
The hot oxygen silicon dioxide layer in face.
[specific embodiment]
In the description of the present invention, it should be noted that term " center ", "upper", "lower", "left", "right", "vertical",
The orientation or positional relationship of the instructions such as "horizontal", "inner", "outside" be based on the orientation or positional relationship shown in the drawings, merely to
Convenient for description the present invention and simplify description, rather than the device or element of indication or suggestion meaning must have a particular orientation,
It is constructed and operated in a specific orientation, therefore is not considered as limiting the invention；Term " first ", " second ", " third "
It is used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance；In addition, unless otherwise specific regulation and limit
Fixed, term " installation ", " connected ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, be also possible to detachably connect
It connects；It can be directly connected, the connection inside two elements can also be can be indirectly connected through an intermediary.For this
For the those of ordinary skill in field, the concrete meaning of above-mentioned term in the present invention can be understood with concrete condition.
In the present invention, for individual measuring unit, the center is set as the inside of measuring unit, setting at periphery
For outside, vertical centerline refers to center line along its length, and cross central line is in the width direction perpendicular to vertical centerline
Center line；Referring to Fig. 1, two adjacent sides of accelerometer chip are set, one in the x-direction, another accelerates in the y-direction
Degree meter chip is the direction z perpendicular to xoy plane in xoy plane；Whichever following measuring unit follow the rule,
It is no longer to illustrate more.
Referring to Fig. 1, the invention discloses a kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation, sensors
Chip is manufactured by soi wafer, and sensor is made of X measuring unit, Y measuring unit, Z measuring unit and chip outline border 5, each
Measuring unit is arranged in chip outline border 5, and is fixedly connected with chip outline border 5, and chip outline border 5 is bonded in bottom glass plate 20
On；The vertical centerline of Z measuring unit is parallel to the vertical centerline of X measuring unit, and the vertical centerline of Y measuring unit is vertical
In the vertical centerline of Z measuring unit；The vertical centerline of Z measuring unit is parallel to the vertical center in the direction y, Y measuring unit
Line is parallel to the direction y, and for entire chip in xoy plane, the direction perpendicular to chip is the direction z；Each measuring unit is wrapped
Respective mass block, supporting beam and sensitive beam are included, three measuring units are respectively used for measuring the acceleration in three directions of x, y, z.
Referring to Fig. 1 and Fig. 2, X measuring unit is identical with the structure of Y measuring unit, two the first measuring block 2 measurements of each freedom
Block forms, two the first measuring blocks 2 parallel arrangement in a measuring unit, i.e., the vertical axis of two the first measuring blocks 2 is flat
Row, each first measuring block 2 are respectively fixedly connected with chip outline border 5；Each first measuring block 2 includes two mass blocks,
Respectively the first mass block 2-1 and the second mass block 2-2, the first mass block 2-1 and the second mass block 2-2 are in its vertical centerline
The intersection of inner side edge is provided with the first gap 2-3, the intersection of its vertical centerline and outer side edges is provided with second and slits
Mouthful 2-4, the first gap 2-3 and the second gap 2-4 are rectangular configuration, and the first of the first mass block 2-1 and the second mass block 2-2
Gap 2-3 is oppositely arranged, and is connected between two the first gap 2-3 by hinge beam 3, so that the inner side edge of the first mass block 2-1
It is fixedly connected with the inner side edge of the second mass block 2-2 by hinge beam 3；Along the transverse direction of measuring unit, the both ends of hinge beam 3 are distinguished
Positioned at the center of the first mass block 2-1 and the second mass block 2-2；First mass block 2-1 and the second mass block 2-2 removes gap
Inner side edge edge in addition is by the first sensitive beam 4-1 connection, and in the present embodiment, the two sides of the first gap 2-3 are each provided with
One the first sensitive beam 4-1, and two the first sensitive beam 4-1 are symmetrical relative to hinge beam 3, while relative to the first measuring unit
2 vertical centerline is symmetrical, and the distance between the first mass block 2-1 and the second mass block 2-2 are the length of the first sensitive beam 4-1
Degree.
The outside of first mass block 2-1 and the second mass block 2-2 are connected with chip outline border 5 by the first supporting beam 1 respectively,
Two the first supporting beams 1 are in the vertical centerline of the first measuring block 2, outside one end of each the first supporting beam 1 and chip
Frame 5 is fixedly connected, the other end be fixed at the second gap 2-4 or the second mass block 2-2 of the first mass block 2-1 second slit
On the inner face of mouth 2-4.
Two the first measuring blocks 2 of X measuring unit are used to measure the acceleration in the direction x, for Y measuring unit two the
One measuring block 2 is used to measure the acceleration in the direction y；It is equal on each first sensitive beam 4-1 in X measuring unit or Y measuring unit
It is provided with varistor；The varistor on two the first sensitive beam 4-1 in X measuring unit passes through metal lead wire 16 and pad
Connection one semi-loop favour stone full-bridge circuit of composition；The varistor on two the first sensitive beam 4-1 in Y measuring unit is logical
It crosses metal lead wire 16 and connects one semi-loop favour stone full-bridge circuit of composition with pad.
Referring to Fig. 3, Z measuring unit is second measuring block 6, and the second measuring block 6 includes third mass block 6-1 and the 4th
The inner side edge of mass block 6-2, third mass block 6-1 and the 4th mass block 6-2 pass through the second sensitive beam 4-2 and third sensitive beam 4-
3 connections；It is provided with the first protrusion 6-3 on the inner side edge of third mass block 6-1 and the first groove 6-4, the first protrusion 6-3 setting exists
At the vertical centerline of second measuring block 6, the first protrusion 6-3 includes the protrusion of the first linkage section 6-3-1 and first of integrally connected
6-3-2 is held, the first linkage section 6-3-1 is by the main part of third mass block 6-1 and the first protruding end 6-3-2 integrally connected
Get up, the width of the first protruding end 6-3-2 is greater than the width of the first linkage section 6-3-1, the self structure of the first protruding end 6-3-2
It is symmetrical both with respect to the vertical centerline of the second measuring block 6 with the self structure of the first linkage section 6-3-1；First protrusion 6-3's
It is two the first groove 6-4 between two sides and the side portion of the second measuring block 6, the structure of two the first groove 6-4 is identical and phase
It is symmetrical for the vertical centerline of the second measuring block 6；4th mass block 6-2 includes the second protrusion 6-5 and the second groove 6-6, the
Two groove 6-6 are arranged at the vertical centerline of the second measuring block 6, and the second groove 6-6 includes front end that is of different size and communicating
The first protruding end 6-3-2 is placed in groove 6-6-1 and rearmost flute 6-6-2, rearmost flute 6-6-2, in the groove 6-6-1 of front end
It is placed with the first linkage section 6-3-1；The two sides of second groove 6-6 are that two second protrusions 6-5, two second protrusion 6-5 are opposite
Symmetrical in the second groove 6-2, i.e., the center line relative to the second measuring block 6 is symmetrical, each second protrusion 6-5 includes the second company
Section 6-5-1 and the second protruding end 6-5-2 are met, the width of the second protruding end 6-5-2 is greater than the width of the second linkage section 6-5-1, the
The outer side edges of two protruding end 6-5-2 and the outer side edges of the second linkage section 6-5-1 are concordant, therefore the inside of the second protruding end 6-5-2
While the inner side edge relative to the second linkage section 6-5-1 is protruded to the inside of the second measuring block 6；It is placed in one the first groove 6-4
There is one second protrusion 6-5.As can be seen from the above description, the third mass block 6-1 and the 4th mass block 6-2 of the second measuring block 6 exist
The center of second measuring block 6 is to match meshing state, i.e., the first protrusion 6-3 and the second groove 6-6 fit engagement relatively, the
The protrusion 6-5 fit engagement of one groove 6-4 and second.Each second protrusion 6-5 is protruded to the vertical centerline of the second measuring block 6
Part connected with the first protruding end 6-3-2 by third sensitive beam 4-3, therefore two second protrusion 6-5 are each by one
A third sensitive beam 4-3 and the first protruding end 6-3-2 connection, every one end of the 4th mass block 6-2 inner side edge is each by one
Second sensitive beam 4-2 is connected with one end of third mass block 6-1 inner side edge；Two third sensitive beam 4-3 are relative to the second measurement
The vertical centerline of block 6 is symmetrical, and two the second sensitive beam 4-2 are symmetrical relative to the vertical centerline of the second measuring block 6.
Referring to fig. 4, the outside of third mass block 6-1 and the 4th mass block 6-2 pass through second supporting beam 8 and core respectively
Piece outline border 5 connects, and the plane of the second supporting beam 8 is parallel to X/Y plane, and third mass block 6-1 or the 4th mass block 6-2 is arranged along Z
At the center of direction thickness；Snakelike beam 7 is provided in second supporting beam 8, the plane of snakelike beam 7 is perpendicular to the second supporting beam 8
Plane；One end of snakelike beam 7 is connected with the outer side edges of third mass block 6-1 or the 4th mass block 6-2, the other end and chip outline border
5 connections；The plane of snakelike beam 7 is between third mass block 6-1 and chip outline border 5 or the 4th mass block 6-2 and chip outline border
Detour is arranged between 5；The snakelike beam 7 includes several serpentine sectors 7-1, and serpentine sector 7-1 exists along the direction x arranged
Between mass block and chip outline border 5, each serpentine sector 7-1 includes orthogonal first plane 7-2 and the second plane 7-
3, the first plane 7-2 are parallel to the cross central line of Z measuring unit, the i.e. direction x, and the second plane 7-3 is parallel to Z measuring unit
Vertical centerline, the direction y, the both ends of each the first plane 7-2 are connected separately with a second plane 7-3；One snakelike list
The length no requirement (NR) of the first plane 7-2, can set according to actual needs in first 7-1；Snake type beam 7 is for extraction wire 16 and does not increase
Add the rigidity of the second supporting beam 8, so that when Z measuring unit is generated deformation by acceleration, the third that is connected by snakelike beam 7
It can deform, while reduce because of and chip outline border 5 with third mass block 6-1 between chip outline border 5 on the outside of mass block 6-1
It is directly connected to and increases the deformation drag of third mass block 6-1；4th mass block 6-2 is similarly.Each second sensitive beam 4-2 and
It is fixedly installed varistor on third sensitive beam 4-3, all varistors pass through 16 He of metal lead wire in Z measuring unit
Pad connection, because in Z measuring unit, when by z to acceleration, existing compression sensitive beam, and have stretching sensitive beam, make
The varistor obtained in sensitive beam is capable of forming favour stone full-bridge.Snakelike beam 7 in Z-direction measuring unit realizing that second is quick
It while feeling beam 4-2 purely axial deformation, also achieves not only to have existed on same structure and stretches sensitive beam, but also there is compression sensitive beam
Function, and then in a structure form favour stone full-bridge, the output sensitivity of Lai Tigao sensor.The sensor chip can
To realize the separating and measuring of 100g or less 3-axis acceleration.
The size of the chip of the implementation ratio sensor is as described below:
The overall dimension of sensor chip are as follows: 410 μm of 6900 μ m of length × width x thickness=6900 μ m；
X, in Y measuring unit the first supporting beam 1 size are as follows: 410 μm of 40 μ m of length × width x thickness=300 μ m；
The size of second supporting beam 8 in Z measuring unit are as follows: 70 μm of 290 μ m of length × width x thickness=1860 μ m；
X, Y measuring unit hinge beam size are as follows: 410 μm of 20 μ m of length × width x thickness=500 μ m；
X, Y, Z measuring unit sensitive beam (including the first sensitive beam 4-1, the second sensitive beam 4-2 and third sensitive beam 4-3) ruler
It is very little: 5 μm of 10 μ m of length × width x thickness=70 μ m；
X, in Y measuring unit the first mass block 2-1 and the second mass block 2-2 size are as follows: length × width x thickness=1530 μm
×1000μm×410μm；
The size of third mass block 6-1 and the 4th mass block 6-2 in Z measuring unit are as follows: length × width x thickness=2800 μ ms
1860μm×410μm；
Wire widths are as follows: 30 μm；
Bonding pad area are as follows: 200 200 μm of μ ms.
The working principle of the sensor chip are as follows:
Referring to Figure 5, it can be obtained by Newton's second law F=ma, when acceleration of the sensor chip by the direction x in face
axWhen effect, the mass block in two the first measuring blocks 2 in X measuring unit is moved due to inertia and in generating surface, causes
The deformation of one supporting beam 1, so as to cause the deformation of the first sensitive beam 4-1, according to the piezoresistive effect of silicon, on the first sensitive beam 4-1
Varistor change in resistance occurs under stress, the relationship between resistance varying-ratio and its suffered stress is as follows:
Wherein: R is the initial resistance value of varistor；
π is the piezoresistance coefficient of varistor；
σ is the stress of varistor；
Δ R is the change in resistance of varistor.
At this point, the semi-loop favour stone full-bridge disequilibrium that four varistors on same operative orientation are constituted, output
With external acceleration axDirectly proportional electric signal realizes the detection to acceleration.The sensitivity S and external acceleration a of sensorx
Relationship such as following formula:
Wherein: UoutFor the output voltage of Wheatstone bridge；
E is the Young's modulus of silicon；
π is piezoresistance coefficient；
UapplyFor the supply voltage of Wheatstone bridge；
ε is the strain of the micro- beam of pressure drag；
π44For Shearing piezoresistance coefficient；
L is the length of sensitive beam；
The axial deformation of Δ l --- sensitive beam；
As acceleration a of the sensor chip by the direction y in faceyWhen effect, two first surveys in Y measuring unit at this time
The first mass block 2-1 and the second mass block 2-2 in gauge block 2 are moved due to inertia and in generating surface, the work of sensor chip
Principle and sensitivity computing method and the sensor chip are by acceleration axShi Xiangtong, which is not described herein again.
Referring to Fig. 6, the working principle of the working principle and X, Y-axis of Z axis is essentially identical, except that when being added by Z axis
When speed, the inside of third mass block 6-1 and the 4th mass block 6-2 make sensitive beam by deflection up and down in the z-direction
Deformation, and due to the winding type end of mass block, so that the deformation state phase of intermediate two groups of sensitive beams and external two groups of sensitive beams
Instead；When external two groups of the second sensitive beam 4-2 is when in a compressed state, the two groups of third sensitive beam 4-3 in centre are in elongation state；
Four groups of sensitive beams form Wheatstone bridge by conducting wire.
The key technical indexes that the chip can reach is as follows:
Range: 0~100g (3-axis acceleration)；
Sensitivity: >=1.6mV/g/3V；
Intrinsic frequency: >=10kHz；
Operating temperature: -40 DEG C~130 DEG C.
The chip that the present embodiment is designed, sensitivity and intrinsic frequency are much higher than existing common accelerometer chip.
Referring to Fig. 7 and Fig. 8, the letter in Fig. 8 Block Diagrams represents the sequence in Fig. 7, the preparation side of the chip in the present invention
Method the following steps are included:
1) referring to (a) figure in Fig. 7, raw material is chosen, N-type (100) crystal face twin polishing soi wafer, soi wafer are used
Including the substrate silicon 12, buried oxide layer 10 and device layer 11 stacked gradually from top to bottom；The material selection BF33 of bottom glass plate 20
Glass；Soi wafer is cleaned, two-sided thermal oxide is carried out at 900 DEG C -1200 DEG C, respectively obtains one layer in the upper and lower surface of silicon wafer
Hot oxygen silicon dioxide layer 9, including the hot oxygen silicon dioxide layer 9-1 in the upper surface and hot oxygen silicon dioxide layer 9-2 in lower surface, as connecing down
It is lightly doped mask layer, while improving ion implantation uniformity.
2) referring to (b) figure in Fig. 7, using version is lightly doped, first time photoetching makes the hot oxygen silicon dioxide layer 9-1's in upper surface
Front patterning removes the hot oxygen silicon dioxide layer 9 in positive lightly doped district 13 using reactive ion etching (RIE) technique,
The hot oxygen silicon dioxide layer 9 in remaining region serves as exposure mask, then carries out boron ion and is lightly doped, forms lightly doped district in device layer 11
13, the lightly doped district 13 is above-mentioned sensitive resistance, each sensitive resistance is fixed in a sensitive beam, passes through
The step prepares the sensitive resistance in all sensitive beams；Then the trap redistributed pushes away diffusion annealing process, guarantees whole
Impurity concentration in a SOI device layer 11 is uniformly distributed.
3) referring to (c) figure in Fig. 7, in one layer photoresist 14 of front surface coated, it is therefore intended that protection lightly doped district 13 is connecing
It is unaffected in the heavy doping step got off；Using heavy doping version, second of photoetching and reactive ion etching (RIE) technique are realized
Silica pattern layers simultaneously remove the hot oxygen silicon dioxide layer 9-1 in the upper surface in the heavily doped region of front and photoresist 14,
The photoresist 14 in remaining region serves as mask, then carries out boron ion heavy doping, and ohm that low resistance is formed in device layer 11 connects
Touch area 15；Carry out redistribution diffusion annealing process, the trap then redistributed push away diffusion annealing process make sensitive resistance and
The impurity concentration of ohmic contact regions 15 is uniformly distributed, with guarantee next step metal lead wire 16 and sensitive beam on varistor it
Between formed be steadily contacted.
4) it referring to (d) figure in Fig. 7, is made in soi wafer front whole surface of physical vapour deposition (PVD) (PVD) technology
Ti/Al layers out, third time photoetching then is carried out using metal pad and conducting wire version, etches other regions in addition to metal lead wire later
Metal layer, form metal lead wire 16 and pad structure 17, and carry out alloying process at high temperature.
5) referring to (e) figure in Fig. 7, layer of silicon dioxide layer 18, institute are formed using pecvd process at the soi wafer back side
The setting of silicon dioxide layer 18 is stated at the hot back side oxygen silicon dioxide layer 9-2 in lower surface, at the same time the hot oxygen silicon dioxide layer in lower surface
9-2 and silicon dioxide layer 18 combine double mask layers as following back-etching.
6) referring to (f) figure in Fig. 7, the back side etches version for the first time, and fourth lithography is in soi wafer photoetching back-etching area
Domain removes the hot oxygen silicon dioxide layer 9-2 in lower surface and silicon dioxide layer 18 in back side deep etching region using RIE technique,
The hot oxygen silicon dioxide layer 9-2 in the lower surface in remaining region and silicon dioxide layer 18 are used as exposure mask；It is in next etch step
Guarantee that the molding supporting beam of institute, hinge beam 3 and a mass block have good edge verticality and depth-to-width ratio, using it is deep react from
Sub- etching technique (Deep Reactive Ion Etching, DRIE) performs etching；X measuring unit is etched away by the step
A part of 3 lower part of the first supporting beam 1 and hinge beam in neutralization Y measuring unit and the first mass block 2-1 and the second mass
A part of the fast lower part 2-2.
7) referring to (g) figure in Fig. 7, the back side etches version for the second time, and the 5th photoetching is in soi wafer photoetching back-etching area
Domain removes the lower surface heat two as mask layer in the 7 back-etching region of the second supporting beam 8 and snakelike beam in Z measuring unit
Silicon oxide layer 9-2 and silicon dioxide layer 18, the mask layer in remaining region serve as exposure mask；The step uses DRIE technique etched substrate
Silicon 12 forms the lower part of the second supporting beam 8, base infrastructure, the snakelike beam 7 of third mass block 6-1 and the 4th mass block 6-2
Lower part, the lower part of the first supporting beam 1, the lower part of hinge beam 3 and and the first mass block 2-1 and the second mass
The base infrastructure of fast 2-2.
8) referring to (h) figure in Fig. 7, using movement clearance domain, the 6th photoetching carries out photoetching to bottom glass plate 19
Glue exposure mask, and wet etching is carried out with KOH, empty slot region 21 is formed, guarantees that acceleration transducer in the operating condition can be normal
Movement；The empty slot region 21 is used to match supporting beam, hinge beam, the sensitive beam, mass block region in acceleration chip；The bottom of at
Cr/Au layer 20 is sputtered on empty slot region 21 in layer glass plate 19, to prevent Electrostatic Absorption.
9) referring to (i) figure in Fig. 7, lower surface thermal silicon dioxide layer of the RIE technique to the soi wafer back side as mask is used
9-2 and silicon dioxide layer 18 perform etching, to expose the substrate silicon 12 at the soi wafer back side；Pass through anode linkage later for chip
In 12 region of substrate silicon be encapsulated on bottom glass plate 19.
10) referring to (j) figure in Fig. 7, the 7th photoetching etches version using positive for the first time, photoetching front etch areas,
The hot oxygen silicon dioxide layer 9-1 in upper surface in positive etch areas is removed using reactive ion etching (RIE) technique, is then coated with
One layer photoresist plays the role of protecting metal lead wire 16 and pad structure 17, utilizes inductive couple plasma (Inductively
Cupled Plasma, ICP) lithographic technique be etched to buried oxide layer 10 stopping, formed the first supporting beam 1, hinge beam 3, sensitive beam 4
And the top half of all mass blocks, form the device layer portions of the second supporting beam 8 and snakelike beam 7.
11) referring to (k) figure in Fig. 7, the 8th photoetching, using second of front etching version, photoetching front second is supported
The region of beam 8 does not remove photoetching using the buried oxide layer 10 in reactive ion etching (RIE) technique removal 8 region of the second supporting beam
Glue plays the role of protecting metal lead wire and pad structure 16.In next etch step in order to guarantee molding snake
Ellbeam 7 has good edge verticality and depth-to-width ratio, here with deep reaction ion etching technology (Deep Reactive
Ion Etching, DRIE) it performs etching, etch away the buried oxide layer 10 of snakelike 7 upper area of beam；So far the second supporting beam 8 and snake
The upper partial etching of ellbeam 7 is completed.
12) referring to (l) figure in Fig. 7, the soi wafer front for having etched completion spraying photoresist is protected, then
Tenth photoetching is removed the photoresist in corresponding 10 region of buried oxide layer using positive third time etching version, then utilizes buffer HF
Acid etches buried oxide layer 10 from front, is utilized respectively naturally dry after deionized water is rinsed with acetone, finally again will be positive
Photoresist removal；
13) for further release, alleviate integrated sensor chip process residual stress (include: mechanical stress,
Stress in thin films, thermal stress etc.), it is handled using low temperature annealing process.
The MEMS three-axis piezoresistance formula accelerometer chip preparation of the purely axial deformation terminates.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention
Within mind and principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.
Claims (10)
1. a kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation characterized by comprising be fixed at core
X measuring unit, Y measuring unit and Z measuring unit in piece outline border (5), three measuring units are isolated by chip outline border (5)；Z
The vertical centerline of measuring unit is parallel to the vertical centerline of X measuring unit, and the vertical centerline of Y measuring unit is perpendicular to Z
The vertical centerline of measuring unit；The chip outline border (5) is bonded on bottom glass plate (19)；Z measuring unit includes third
The outer side edges of mass block (6-1) and the 4th mass block (6-2), third mass block (6-1) and the 4th mass block (6-2) pass through one
A second supporting beam (8) and chip outline border (5) connection；The first protrusion (6- is provided on the inner side edge of third mass block (6-1)
3), the two sides of first raised (6-3) are respectively arranged with first groove (6-4)；It is set on the inner side edge of 4th mass block (6-2)
It is equipped with the second groove (6-6), the two sides of the second groove (6-6) are respectively arranged with one second raised (6-5)；First protrusion (6-
3) it is engaged in the second groove (6-6), each second raised (6-5) is engaged in second groove (6-6)；Each
Two raised (6-5) pass through third sensitive beam (4-3) and first raised (6-3) connection；Third mass block (6-1) and the 4th mass block
Two outer ends of (6-2) inner side edge pass through the second sensitive beam (4-2) connection respectively；
Varistor in second sensitive beam (4-2) and third sensitive beam (4-3) by metal lead wire (16) connection formed favour this
Logical full-bridge.
2. a kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation according to claim 1, feature exist
In the plane of second supporting beam (8) is parallel to X/Y plane, and the plane of the second supporting beam (8) is arranged in third mass block (6-
Or the centerline in the 4th direction mass block (6-2) z 1)；Snakelike beam (7) are fixedly installed in second supporting beam (8).
3. a kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation according to claim 2, feature exist
In the snakelike beam (7) includes several serpentine sectors (7-1)；Each serpentine sector (7) is fixed at third mass block
Between (6-1) and chip outline border (5), or it is fixed between the 4th mass block (6-2) and chip outline border (5)；The snake
Shape unit (7-1) includes orthogonal first plane (7-2) and the second plane (7-3), and the first plane (7-2) is parallel to Z survey
The cross central line of unit is measured, the second plane (7-3) is parallel to the vertical centerline of Z measuring unit, each first plane (7-
2) both ends are connected separately with second plane (7-3).
4. a kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation according to claim 1, feature exist
In described first raised (6-3) includes the first linkage section (6-3-1) and the first protruding end (6-3-2) of integrally connected, and first connects
Section (6-3-1) is connect by third mass block (6-3) main body and the first protruding end (6-3-2) integrally connected, the first protruding end (6-3-2)
Width be greater than the first linkage section (6-3-1) width；Second raised (6-5) includes that the second linkage section (6-5-1) and second are convex
Outlet (6-5-2), the second linkage section (6-5-1) connect the 4th mass block (6-4) main body and the second protruding end (6-5-2), the
The width of two protruding ends (6-5-2) is greater than the width of the second linkage section (6-5-1)；Each second protruding end (6-5-2) passes through
One third sensitive beam (4-3) and the first protruding end (6-3-2) connection.
5. a kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation according to claim 4, feature exist
In two the second sensitive beams (4-2) are separately positioned on the outside of second linkage section (6-5-1).
6. a kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation according to claim 1, feature exist
In X measuring unit is identical with the structure of Y measuring unit, two the first measuring block (2) compositions of each freedom, each first measurement
It include the first mass block (2-1) and the second mass block (2-2) in block (2), the first mass block (2-1) and the second mass block (2-2)
Outer side edges pass through first supporting beam (1) and chip outline border (5) connection, the first mass block (2-1) and the second mass block
The inner side edge of (2-2) is connected by hinge beam (3) and the first sensitive beam (4-1)；
The varistor in the first sensitive beam (4-1) in X measuring unit forms favour stone half by metal lead wire (16) connection
Bridge；The varistor in the first sensitive beam (4-1) in Y measuring unit forms favour stone half by metal lead wire (16) connection
Bridge.
7. a kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation according to claim 6, feature exist
In the inner side edge of the first mass block (2-1) and the second mass block (2-2) is provided with the first gap (2-3), two the first gap
(2-3) is symmetrical arranged relative to the cross central line of the first measuring block (2)；It slits respectively with two first at the both ends of hinge beam (3)
The inner face of mouth (2-3) is fixedly connected；Hinge beam (3) is arranged in the vertical centerline of the first measuring block (2).
8. a kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation according to claim 6, feature exist
In, the inner side edge of the first mass block (2-1) and the second mass block (2-2) by two the first sensitive beams (4-1) connections, two the
One sensitive beam (4-1) is separately positioned on the two sides of the first gap (2-3), and two the first sensitive beams (4-1) are relative to hinge beam (3)
Symmetrically.
9. a kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation according to claim 6, feature exist
In being provided with the second gap (2-4) on the outside of the first mass block (2-1) and the second mass block (2-2)；Each first support
One end of beam (1) is fixedly connected with chip outline border (5), and the inner face of the other end and the second gap (2-4) is fixedly connected；First
Beam (1) is supportted to be arranged in the vertical centerline of the first measuring block (2).
10. a kind of preparation method of the MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation described in claim 1,
It is characterized in that, comprising the following steps:
1) two-sided thermal oxide is carried out to soi wafer, is respectively formed one layer of hot oxygen titanium dioxide in the upper and lower surfaces of soi wafer
The hot oxygen silicon dioxide layer (9-2) of the hot oxygen silicon dioxide layer (9-1) of silicon layer (9), respectively upper surface and lower surface；
2) it using version is lightly doped, is removed by photoetching and reaction ionic etching method upper in the lightly doped region of the upper surface SOI
Surface heat oxygen silicon dioxide layer (9-1) after adulterating boron ion in lightly doped region, is formed lightly doped district (13)；
3) heavy doping version is utilized, the hot oxygen dioxy in upper surface in heavily doped region is removed by photoetching and reaction ionic etching method
SiClx layer (9-1) carries out heavy doping in heavily doped region, is formed ohmic contact regions (15)；
4) metal pad and conducting wire version progress light are passed through by physical vapor deposition method depositing Ti/Al layer in soi wafer front
It carves, forms metal lead wire (16) and pad structure (17)；
5) layer of silicon dioxide layer (18) are deposited by vapour deposition process at the back side of the hot oxygen silicon dioxide layer (9-2) in lower surface,
The hot oxygen silicon dioxide layer (9-2) in lower surface and silicon dioxide layer (18) form double mask layers；
6) double mask layers in the deep etching region of the soi wafer back side are removed by reaction ionic etching method, so that soi wafer is deep
Substrate silicon (12) in etch areas is exposed；By deep reaction ion etching method etched substrate silicon (12), it is single to etch away X measurement
A part and the first mass block (2-1) and second of first supporting beam (1) and hinge beam (3) lower part in member and Y measuring unit
A part of the lower part mass block (2-2)；
7) double mask layers of the second supporting beam (8) and snakelike beam (7) back-etching region in Z measuring unit are removed by photoetching；
Continue to etch by deep reaction ion etching method, forms the lower part of the second supporting beam (8), the lower part of snakelike beam (7), the
Lower part, the lower part of hinge beam (3) and the base infrastructure of all mass blocks of one supporting beam (1)；
8) by movement clearance domain, photoresist exposure mask is carried out to bottom glass plate (19), wet etching, In are carried out by KOH
Empty slot region (21) are formed on bottom glass plate (19)；
9) it is performed etching by deep reaction ion etching method double mask layers remaining to the soi wafer back side, so that soi wafer
Substrate silicon (12) is exposed；Substrate silicon (12) region is encapsulated on bottom glass plate (19) by anode linkage；
10) the hot oxygen silicon dioxide layer (9-1) in upper surface of removal soi wafer, coating one are etched by reaction ionic etching method
Then layer photoresist is etched to buried oxide layer (10) by inductively coupled plasma etching method and stops, forming the first supporting beam
(1), the upper part of hinge beam (3), sensitive beam (4) and all mass blocks forms the second supporting beam (8) and snakelike beam (7)
Device layer portions；
11) device layer and buried oxide layer (10) that the second supporting beam (8) upper surface is removed by reaction ionic etching method, then lead to
Cross device layer and buried oxide layer (10) that reaction deep ion lithographic method etches away snakelike beam (7) upper area, the second supporting beam (8)
It is completed with the upper partial etching of snakelike beam (7)；
12) the soi wafer front for having etched completion spraying photoresist is protected, removes the light in corresponding buried oxide layer (10) region
Photoresist, then using the remaining buried oxide layer (10) in buffer etching soi wafer front, naturally dry after cleaning soi wafer is positive,
Finally the positive photoresist of soi wafer is removed again；
13) soi wafer, the MEMS three-axis piezoresistance formula accelerometer chip production of purely axial deformation are handled using low temperature annealing process
It completes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910683519.7A CN110531114B (en) | 2019-07-26 | 2019-07-26 | Pure axial deformation MEMS triaxial piezoresistive accelerometer chip and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910683519.7A CN110531114B (en) | 2019-07-26 | 2019-07-26 | Pure axial deformation MEMS triaxial piezoresistive accelerometer chip and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110531114A true CN110531114A (en) | 2019-12-03 |
| CN110531114B CN110531114B (en) | 2020-07-28 |
Family
ID=68660536
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910683519.7A Active CN110531114B (en) | 2019-07-26 | 2019-07-26 | Pure axial deformation MEMS triaxial piezoresistive accelerometer chip and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110531114B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111157761A (en) * | 2020-01-02 | 2020-05-15 | 西安交通大学 | Temperature self-compensation in-plane double-axis acceleration sensor and temperature compensation method |
| CN111238461A (en) * | 2020-03-09 | 2020-06-05 | 中国建筑材料科学研究总院有限公司 | Harmonic oscillator and preparation method thereof |
| CN111351962A (en) * | 2020-04-15 | 2020-06-30 | 芜湖天波光电技术研究院有限公司 | Missile-borne recorder with three-way impact sensor chip |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01239466A (en) * | 1988-03-18 | 1989-09-25 | Fujikura Ltd | Manufacture of semiconductor acceleration sensor |
| CN1415968A (en) * | 2002-12-13 | 2003-05-07 | 中国科学院上海微系统与信息技术研究所 | Single chip integrated acceleration transducer of piezoresistance for micro girder construction in straight pull and vertical compression as well as its preparation method |
| EP1887365A2 (en) * | 2006-08-09 | 2008-02-13 | Hitachi Metals, Ltd. | Multi-range three-axis acceleration sensor device |
| CN201083760Y (en) * | 2007-10-19 | 2008-07-09 | 中国电子科技集团公司第十三研究所 | Three axis integrated piezoresistance type acceleration sensor |
| CN102476786A (en) * | 2010-11-22 | 2012-05-30 | 中国科学院上海微系统与信息技术研究所 | Single silicon chip integrated chip combining acceleration sensor and pressure sensor and manufacturing method of single silicon chip integrated chip |
| CN102841217A (en) * | 2012-09-07 | 2012-12-26 | 中北大学 | Tri-axial accelerometer with giant magneto-resistance effect |
| CN102928622A (en) * | 2012-10-17 | 2013-02-13 | 中北大学 | Beam island tower shaped piezoresistive type three-axis micro-electro-mechanical system (MEMS) high-range acceleration sensor array |
| CN103777037A (en) * | 2014-01-10 | 2014-05-07 | 西安交通大学 | Multi-beam double-mass-block acceleration sensor chip and preparation method thereof |
| CN104181331A (en) * | 2014-08-27 | 2014-12-03 | 电子科技大学 | Piezoresistive acceleration sensor and manufacturing method thereof |
| CN106053881A (en) * | 2016-08-22 | 2016-10-26 | 中国科学院上海微系统与信息技术研究所 | Single-chip silicon-integrated three-axis high-bandwidth high-impact accelerometer and manufacturing method thereof |
| CN107817364A (en) * | 2017-09-30 | 2018-03-20 | 西安交通大学 | A kind of axis accelerometer chip of MEMS straight pull and vertical compressions formula two and preparation method thereof |
| CN208443865U (en) * | 2018-04-20 | 2019-01-29 | 黑龙江大学 | A kind of monolithic integrated tri-axial acceleration sensor |
-
2019
- 2019-07-26 CN CN201910683519.7A patent/CN110531114B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01239466A (en) * | 1988-03-18 | 1989-09-25 | Fujikura Ltd | Manufacture of semiconductor acceleration sensor |
| CN1415968A (en) * | 2002-12-13 | 2003-05-07 | 中国科学院上海微系统与信息技术研究所 | Single chip integrated acceleration transducer of piezoresistance for micro girder construction in straight pull and vertical compression as well as its preparation method |
| EP1887365A2 (en) * | 2006-08-09 | 2008-02-13 | Hitachi Metals, Ltd. | Multi-range three-axis acceleration sensor device |
| CN201083760Y (en) * | 2007-10-19 | 2008-07-09 | 中国电子科技集团公司第十三研究所 | Three axis integrated piezoresistance type acceleration sensor |
| CN102476786A (en) * | 2010-11-22 | 2012-05-30 | 中国科学院上海微系统与信息技术研究所 | Single silicon chip integrated chip combining acceleration sensor and pressure sensor and manufacturing method of single silicon chip integrated chip |
| CN102841217A (en) * | 2012-09-07 | 2012-12-26 | 中北大学 | Tri-axial accelerometer with giant magneto-resistance effect |
| CN102928622A (en) * | 2012-10-17 | 2013-02-13 | 中北大学 | Beam island tower shaped piezoresistive type three-axis micro-electro-mechanical system (MEMS) high-range acceleration sensor array |
| CN103777037A (en) * | 2014-01-10 | 2014-05-07 | 西安交通大学 | Multi-beam double-mass-block acceleration sensor chip and preparation method thereof |
| CN104181331A (en) * | 2014-08-27 | 2014-12-03 | 电子科技大学 | Piezoresistive acceleration sensor and manufacturing method thereof |
| CN106053881A (en) * | 2016-08-22 | 2016-10-26 | 中国科学院上海微系统与信息技术研究所 | Single-chip silicon-integrated three-axis high-bandwidth high-impact accelerometer and manufacturing method thereof |
| CN107817364A (en) * | 2017-09-30 | 2018-03-20 | 西安交通大学 | A kind of axis accelerometer chip of MEMS straight pull and vertical compressions formula two and preparation method thereof |
| CN208443865U (en) * | 2018-04-20 | 2019-01-29 | 黑龙江大学 | A kind of monolithic integrated tri-axial acceleration sensor |
Non-Patent Citations (5)
| Title |
|---|
| YU XU ET AL.: "A Novel Piezoresistive Accelerometer Featuring In-plane Vibration", 《IEEE INTERNATIONAL CONFERENCE ON ELECTRON DEVICES AND SOLID-STATE CIRCUITS》 * |
| YU XU ET AL.: "A Novel Piezoresistive Accelerometer with SPBs to Improve the Tradeoff between the Sensitivity and the Resonant Frequency", 《SENSORS》 * |
| YU XU ET AL.: "Analysis and design of a novel piezoresistive accelerometer with axially stressed self-supporting sensing beams", 《SENSORS AND ACTUATORS A》 * |
| 刘岩等: "多梁结构压阻式测振加速度传感器", 《西安交通大学学报》 * |
| 田雷等: "单片集成三轴加速度传感器", 《半导体技术》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111157761A (en) * | 2020-01-02 | 2020-05-15 | 西安交通大学 | Temperature self-compensation in-plane double-axis acceleration sensor and temperature compensation method |
| CN111157761B (en) * | 2020-01-02 | 2021-11-19 | 西安交通大学 | Temperature self-compensation in-plane double-axis acceleration sensor and temperature compensation method |
| CN111238461A (en) * | 2020-03-09 | 2020-06-05 | 中国建筑材料科学研究总院有限公司 | Harmonic oscillator and preparation method thereof |
| CN111351962A (en) * | 2020-04-15 | 2020-06-30 | 芜湖天波光电技术研究院有限公司 | Missile-borne recorder with three-way impact sensor chip |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110531114B (en) | 2020-07-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107907710B (en) | A kind of two axle acceleration sensor chip of MEMS piezoresistive and preparation method thereof | |
| JP4871513B2 (en) | Micromechanical device with thinly formed cantilever structure and related method | |
| US9702893B2 (en) | In-plane piezoresistive detection sensor | |
| CN107796955B (en) | Double-shaft acceleration sensor chip and preparation method thereof in more beam type single mass face | |
| CN107817364B (en) | A kind of two axis accelerometer chip of MEMS straight pull and vertical compression formula and preparation method thereof | |
| CN105137120B (en) | A kind of V-beam torsional pendulum type single shaft micro-mechanical accelerometer and preparation method thereof | |
| CN110531114A (en) | A kind of MEMS three-axis piezoresistance formula accelerometer chip of purely axial deformation and preparation method thereof | |
| CN110389237B (en) | In-plane double-shaft acceleration sensor chip and preparation method thereof | |
| CN102759637B (en) | MEMS (micro electro mechanical system) triaxial acceleration transducer and manufacture method thereof | |
| CN110371921B (en) | In-plane double-shaft piezoresistive acceleration sensor chip and preparation method thereof | |
| CN111103073A (en) | Multi-parameter cooperative sensitive resonant pressure sensor and preparation method thereof | |
| CN113702665B (en) | MEMS accelerometer and forming method thereof | |
| CN105021846A (en) | Six-axis integrated miniature acceleration sensor and manufacturing method therefor | |
| CN109001490A (en) | High-sensitivity torsional pendulum type silicon micro-accelerometer and preparation method thereof | |
| CN109444469A (en) | A kind of full silicon carbide MEMS triaxial accelerometer and its manufacturing method | |
| CN110780088A (en) | Multi-bridge tunnel magnetic resistance double-shaft accelerometer | |
| CN110531115B (en) | MEMS piezoresistive triaxial impact accelerometer chip with pure axial deformation sensitive beam and preparation method thereof | |
| CN100492015C (en) | Micromechanical capacitance type acceleration sensor manufactured by wet-corrosion | |
| CN113156162B (en) | Accelerometer structure, manufacturing method thereof and acceleration measuring method | |
| CN107782915A (en) | Silicon hollow beam, silicon micro-accelerometer based on silicon hollow beam and preparation method of silicon micro-accelerometer | |
| CN106053881B (en) | Single-chip silicon integrates high bandwidth high-impact acceleration meter of three axis and preparation method thereof | |
| CN110526200A (en) | Piezoresistive accelerometer chip and preparation method thereof outside a kind of face with purely axial deformation sensitive beam | |
| CN105277741A (en) | Transverse MEMS acceleration sensitive chip and manufacturing process thereof | |
| CN113985072A (en) | Double-parallel spiral beam and MEMS accelerometer thereof | |
| CN101323426B (en) | Minisize inertia device structure in overweight mass block surface and manufacturing 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 |