CN107328449B - A kind of thermoelectric pile formula gas flow sensor and preparation method thereof - Google Patents
A kind of thermoelectric pile formula gas flow sensor and preparation method thereof Download PDFInfo
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- CN107328449B CN107328449B CN201710548160.3A CN201710548160A CN107328449B CN 107328449 B CN107328449 B CN 107328449B CN 201710548160 A CN201710548160 A CN 201710548160A CN 107328449 B CN107328449 B CN 107328449B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
- G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
- G01F1/688—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element
- G01F1/6888—Thermoelectric elements, e.g. thermocouples, thermopiles
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Abstract
The present invention provides a kind of thermoelectric pile formula gas flow sensor and preparation method thereof, and structure includes: substrate, has a groove, is opened in upper surface of substrate；First medium film is covered in above groove, is connected with substrate, and surround a heat-insulated cavity jointly with substrate；Heating element is located at first medium film surface；At least two sensing elements are located on first medium film, and are set to heating element two sides, including at least one set of monocrystalline silicon-metal fever couple group, and monocrystalline silicon-metal fever couple group includes several monocrystalline silicon-metal fever couple.Single silicon-chip single side manufacturing technology of the invention is combined through the above scheme, the highest p type single crystal silicon of Seebeck coefficient-gold thermocouple pair is processed on common monocrystalline silicon piece, and thermocouple pair and heating element are isolated by heat-insulated cavity with substrate, the heat dissipation for utmostly reducing adding thermal resistance improves the detection sensitivity of sensor.In addition, inventive sensor size it is small, it is at low cost, be suitable for produce in enormous quantities.
Description
Technical field
The invention belongs to silicon micro mechanical sensor technical fields, more particularly to a kind of thermoelectric pile formula gas flow sensor
And preparation method thereof.
Background technique
Gas flow is the call parameter of industrial processes, scientific research and various business accounting, the survey of gas flow
Amount occupies an important position in the industrial production.In recent years, due to process industrial, energy meter, urban public utilities convection current
The demand sharp increase of measurement, wherein thermal flow rate sensor is widely applied since structure is simply easy to be miniaturized.As
The Typical Representative of thermal flow rate sensor, thermoelectric pile formula gas flow sensor mainly have following advantage: temperature inputs i.e.
The energy output that can be used as it, requires no power to thermal signal switching to electric signal；It is answered with self-produced come into force, ability when having temperature difference
Output voltage is had, so output voltage is without compensation and null offset；In addition, only needing voltmeter when test, it is convenient to operate.Cause
This, with being constantly progressive for MEMS manufacturing technology, thermoelectric pile formula gas flow sensor with its high-performance, low cost, be easy to letter
Number processing etc. advantages wait until to be widely applied in fields such as automotive electronics, aerospace, biochemical medicines.
The working principle of thermoelectric pile formula gas flow sensor is based on Seebeck effect (Seebeck Effect), measurement
Because fluid flowing causes the asymmetrical variable quantity of heater both ends temperature, so that it is determined that fluid flow rate.Therefore, thermocouple is improved to plug
Seebeck coefficient and reduction device size are the development trends of thermoelectric pile formula gas flow sensor.
It is limited at present by manufacture craft, the much lower crystal silicon-metallic combination of Seebeck coefficient is mostly used on non-soi wafer,
Sensor detection performance is improved to brachium mode to quantity or increase thermocouple by increasing thermocouple；In addition, thermoelectric pile formula flow
Sensor is mostly on (100) silicon wafer based on two-sided micromachined, and the units test sensitivity made in this way is low, and chip
Size is larger, and cost of manufacture is high, is unfavorable for mass manufacture.
Meanwhile in order to reduce chip size, improve detection sensitivity, numerous studies are had also been made in scientific worker, but are difficult to
Take into account highly sensitive and micromation.
In order to reduce chip size, G.Kaltsas in 1999 et al. uses p-type polysilicon-aluminum metal as thermocouple material, uses
Porous silicon as dielectric layer using single side micromachined mode manufacture gas flow sensor [Kaltsas G,
Nassiopoulou A.G.Novel C-MOS compatible monolithic silicon gas flow sensor
with porous silicon thermal isolation[J].Sensors and Actuators A:Physical,
1999,76(1):133-138.].Although this thermoelectric pile formula gas flow sensor realizes the production of single silicon-chip single side, reduce
Chip size, but the thermoelectric pile formula flow sensor of this technique preparation has the following insufficient: (1) cannot achieve list
The production of crystal silicon-metal thermocouple arm, causes sensor detection sensitivity to be limited by Seebeck coefficient；(2) porous silicon have compared with
Big internal stress will appear different degrees of crack phenomenon for a long time in air, will affect the performance of sensor；(3) it generates
The chemical reaction process of porous silicon is complicated, and molding situation is difficult to accurately control, and this defect can bring not sensor yield rate
Benefit influences；(4) use of this porous silicon technology has limitation, and no IC semiconductor foundry can run such spy
Different technique；(5) thermal conductivity of porous silicon will be much higher than air, cause developed sensor heat dissipation bigger.
In order to improve detection sensitivity, the D.Randjelovi ü et al. of IHTM-IMTM company in 2002 uses Seebeck coefficient
High p-type monocrystalline silicon-Jin Zuowei thermocouple material development gas flow sensor [Randjelovic D, Kaltsas G, Lazic
Z,et al.Multipurpose thermal sensor based on Seebeck effect[C],Proc.23rd
International Conference on Microelectronics(MIEL 2002),2002,1:261-264.].First
30 μm wide p type single crystal silicon thermocouple arm is formed in N-type silicon substrate upper heavy doping boron；Then thermocouple pair is formed with golden thermocouple arm；Finally
Monocrystalline silicon is thinned by silicon chip back side wet etching to form thin layer monocrystalline silicon+SiO2 insulation medium film.Although the device is one
Determine the sensitivity that gas flow sensor is improved in degree, but there are still following deficiencies: (1) sensor adding thermal resistance
The deielectric-coating at place is that thin layer monocrystalline silicon+SiO2 is composed, and since monocrystalline silicon thermal conductivity coefficient is big, causes sensor heat dissipation high
And then the detection sensitivity of sensor is reduced to a certain extent；(2) silicon wafer is thinned to thin layer monocrystalline silicon+SiO2 in back side wet etching
Deielectric-coating, etching time are not easy to control, if the too long thermocouple that will lead to of etching time is to being corroded；(3) by (100) silicon wafer wet process
Etching characteristic is it is found that medium membrane area and monocrystalline silicon backside mask open areas ratio very little, and silicon wafer thickness is bigger, chip
Size is bigger, and cost is higher.
To sum up, Conventional thermoelectric heap formula gas flow sensor is difficult to take into account highly sensitive and micromation.Piotto in 2016
Et al. using p-type polysilicon-N-type polycrystalline silicon as thermocouple to develop a half-way house thermoelectric pile formula gas flow sensing
Device [Massimo Piotto, Francesco Del Cesta, Paolo Bruschi, Integrated smart gas flow
sensor with 2.6mW total power consumption and 80dB dynamic range[J]
.Microelectronic Engineering,2016,159:159-163].The chip is made of single silicon-chip single side, chip
Size greatly reduces.In addition, p-type polysilicon-N-type polycrystalline silicon thermocouple pair Seebeck coefficient (about 200 μ V/K of Seebeck coefficient)
Relative to being the Seebeck coefficient (about 450 μ V/K of Seebeck coefficient) of thermocouple arm although wanting far short of what is expected using monocrystalline silicon, relatively
It to be improved much in p-type polysilicon-metal fever couple.Accordingly, with respect to previously reported thermoelectric pile formula gas flow sensor,
The sensor that Piotto et al. is developed is in addition to there are also obtain very big progress in external manufacture craft to be hoisted for sensitivity.But
Piotto et al. could not still solve to make p type single crystal silicon-metal fever by single silicon-chip single-sided process using common monocrystalline silicon piece
The technical problem of couple.
Therefore, it designs and a kind of can solve the problems such as heat dissipation in the prior art is high, size is big, at high cost, performance is low
Thermoelectric pile formula gas flow sensor is necessary.
Summary of the invention
In view of the foregoing deficiencies of prior art, the purpose of the present invention is to provide a kind of thermoelectric pile formula gas flow biographies
Sensor and preparation method thereof, for solving in the prior art, thermoelectric pile formula gas flow sensor heat dissipation is high, size is big, cost
High, the problems such as performance is low.
In order to achieve the above objects and other related objects, the present invention provides a kind of thermoelectric pile formula gas flow sensor, packet
It includes:
Substrate, has a groove, and the groove is opened in the upper surface of the substrate；
First medium film is covered in above the groove, and is connected with the substrate, the first medium film with it is described
Substrate surrounds a heat-insulated cavity jointly；
Heating element is located at the first medium film surface；And
At least two sensing elements are located on the first medium film, and are set to the two sides of the heating element, described
Sensing element includes at least one set of monocrystalline silicon-metal fever couple group, and the monocrystalline silicon-metal fever couple group includes several monocrystalline
Silicon-metal thermocouple pair.
As a preferred solution of the present invention, the first medium film includes several groove profiles for running through its upper and lower surface
Structure, the trench structure and the monocrystalline silicon-metal fever couple group are arranged in parallel and alternate intervals are arranged.
As a preferred solution of the present invention, the monocrystalline silicon-metal fever couple includes monocrystalline silicon thermocouple arm and metal
Thermocouple arm, the monocrystalline silicon thermocouple arm are located at the first medium film close to the surface of the groove side, the metal thermocouple
Arm includes vertical component effect and horizontal part, and the vertical component effect is connected through the first medium film with the monocrystalline silicon thermocouple arm, institute
Horizontal part is stated to be connected with the vertical component effect and be located at surface of the first medium film far from the groove side.
As a preferred solution of the present invention, the heating element is located at the first medium film close to the groove one
The surface of side.
As a preferred solution of the present invention, the substrate is (111) monocrystalline silicon.
As a preferred solution of the present invention, the first medium film includes the TEOS passivation being sequentially stacked from bottom to top
Layer and silicon nitride layer, further include oxide layer between the first medium film and the substrate.
As a preferred solution of the present invention, the heating element is arranged along<110>crystal orientation, the monocrystalline silicon-metal
Thermocouple is arranged to along<211>crystal orientation.
It as a preferred solution of the present invention, further include second medium film, the second medium film is covered in the list
The upper surface of crystal silicon-metal fever couple group and the surrounding first medium film, for protecting the monocrystalline silicon-metal thermocouple
It is right.
As a preferred solution of the present invention, further include several lead pad, be located on the substrate, and be set to
The both ends of the heating element and each sensing element.
As a preferred solution of the present invention, further include ambient resistance element, be set on the substrate.
As a preferred solution of the present invention, the ambient resistance element, the heating element and the monocrystalline silicon-
Monocrystalline silicon thermocouple arm in metal fever couple is boron doped monocrystalline silicon.
The present invention also provides a kind of preparation methods of thermoelectric pile formula gas flow sensor, the preparation method is that of the invention
The preparation method of the thermoelectric pile formula gas flow sensor of the offer, includes the following steps:
1) substrate is provided, and in defining heating element area and at least two sensing element areas, institute on the substrate
It states sensing element area and is located at heating element area two sides, and including at least one monocrystalline silicon-metal fever couple group area, the list
Crystal silicon-metal fever couple group area includes several monocrystalline silicon-metal fever couple area；
2) substrate is etched to form first groove, for defining heating element and monocrystalline silicon-metal fever couple
In monocrystalline silicon thermocouple arm where position and thickness；
3) Yu Suoshu first groove side wall forms side wall protective layer, and in being formed with described the first of the side wall protective layer
Deposited sacrificial layer in groove；
4) first medium membrane layers are deposited in the obtained body structure surface of step 3), and etches the first medium membrane material
The bed of material exposes the monocrystalline to exposing the corresponding substrate area of the heating element to form heating element connecting hole
The corresponding substrate area of monocrystalline silicon thermocouple arm of silicon-metal thermocouple centering is to form monocrystalline silicon thermocouple arm connecting hole；
5) in the surface deposited metal layer of the obtained structure of step 4) and to its it is graphical, to form the monocrystalline silicon-
Metal thermocouple arm in metal fever couple, the metal thermocouple arm include vertical component effect and horizontal part, and the vertical component effect is through described
First medium membrane layers, the horizontal part are connected with the vertical component effect and are located at first medium membrane layers surface；
6) etch step 5) to form second groove, the second groove is located at the adjacent monocrystalline silicon-for obtained structure
Between metal fever couple group area and/or the monocrystalline silicon-is between metal fever couple group area and the substrate；
7) heat-insulated cavity is formed by substrate described in window erodable section of the second groove, to discharge the first medium
Film and the monocrystalline silicon thermocouple arm, wherein the first medium film is connected with the substrate, and encloses jointly with the substrate
At the heat-insulated cavity, the monocrystalline silicon thermocouple arm and the metal thermocouple arm constitute the monocrystalline silicon-metal fever couple, and shape
At sensing element.
As a preferred solution of the present invention, between step 1) and step 2), further include to the heating element area with
And the sensing element area carries out boron doped step.
It as a preferred solution of the present invention, further include to the structure after boron doping after carrying out the boron doping technique
The step of being annealed.
As a preferred solution of the present invention, in step 3), the side wall of Yu Suoshu first groove forms side wall protective layer
Specific steps are as follows:
3-1) the body structure surface deposited sidewalls protected material bed of material obtained in step 2), the side-wall material protective layer include certainly
The TEOS layer and silicon nitride layer being sequentially depositing on down；
The side wall protected material bed of material on the first groove bottom and the surrounding substrate is removed, 3-2) with shape
At the side wall protective layer for being located at the first groove side wall.
It as a preferred solution of the present invention, further include in the obtained knot of step 5) between step 5) and step 6)
Structure surface deposits the step of second medium membrane layers, and the second medium membrane layers are for protecting the sensing element.
As a preferred solution of the present invention, in step 6), the specific steps for forming the second groove include:
6-1) etch the first medium membrane layers of the second groove region；
6-2) continue to etch predetermined depth along the second groove region, to form the second groove.
As a preferred solution of the present invention, substrate described in step 1) is (111) monocrystalline silicon, employed in step 7)
Etchant solution be tetramethyl Dilute Ammonia Solution.
As a preferred solution of the present invention, in step 7), the first medium film of release includes several groove profiles
Structure, wherein the trench structure is formed by the second groove, the trench structure and the monocrystalline silicon-metal fever couple
Group is arranged in parallel and alternate intervals are arranged.
As described above, thermoelectric pile formula gas flow sensor and preparation method thereof of the invention, has the advantages that
1) the single-chip single side manufacturing technology that the present invention is designed and innovated by cleverly structure, in common (111) monocrystalline
The highest p type single crystal silicon of Seebeck coefficient-gold thermocouple pair is processed on silicon wafer；
2) thermoelectric pile formula gas flow sensor of the invention is by thermocouple pair and heating element by being located at immediately below it
Heat-insulated cavity be isolated with substrate, utmostly reduce the heat dissipation of adding thermal resistance, substantially increase sensor detection spirit
Sensitivity；
3) entire flow sensor of the invention is all from the same surface of monocrystalline silicon piece progress processing and fabricating, therefore chip
Size is small, at low cost, is suitable for producing in enormous quantities.
Detailed description of the invention
Fig. 1 is shown as the global structure schematic diagram of thermoelectric pile formula gas flow sensor provided by the invention.
Fig. 2 is shown as thermoelectric pile formula gas flow sensor three-dimensional structure diagrammatic cross-section provided by the invention.
The structure that Fig. 3 to Figure 14 is shown as each step of preparation process of thermoelectric pile formula gas flow sensor of the invention is shown
It is intended to:
Fig. 3 is shown as providing the structural schematic diagram of substrate in gas flow sensor preparation process of the invention；
Fig. 4 is shown as defining heating element in gas flow sensor preparation process of the invention and sensing element structure shows
It is intended to；
Fig. 5 is shown as forming the structural schematic diagram of first groove in gas flow sensor preparation process of the invention；
Fig. 6 is shown as the structural representation of the deposited sidewalls protected material bed of material in gas flow sensor preparation process of the invention
Figure；
Fig. 7 is shown as forming the structural schematic diagram of side wall protective layer in gas flow sensor preparation process of the invention；
Fig. 8 is shown as forming the structural representation of polysilicon sacrificial layer in gas flow sensor preparation process of the invention
Figure；
The structure that Fig. 9 is shown as being formed first medium membrane layers in gas flow sensor preparation process of the invention is shown
It is intended to；
Figure 10 is shown as forming the structural representation of monocrystalline silicon connecting hole in gas flow sensor preparation process of the invention
Figure；
Figure 11 is shown as forming the structural schematic diagram of metal thermocouple arm in gas flow sensor preparation process of the invention；
The structure that Figure 12 is shown as being formed second medium material layer in gas flow sensor preparation process of the invention is shown
It is intended to；
Figure 13 is shown as forming the structural schematic diagram of second groove in gas flow sensor preparation process of the invention；
Figure 14 is shown as the structural representation that corrosion in gas flow sensor preparation process of the invention discharges heat-insulated cavity
Figure；
Figure 15 is shown as each process flow chart in thermoelectric pile formula gas flow sensor preparation process of the invention.
Component label instructions
1 substrate
11 grooves
12 boron ion injection regions
13 oxide layers
14 first grooves
141 side wall protective layers
1411 TEOS layers
1412 silicon nitride layers
142 polysilicon sacrificial layers
2 first medium films
21 trench structures
22 first medium membrane layers
221 silicon nitride layers
222 TEOS passivation layers
23 monocrystalline silicon connecting holes
3 heating elements
4 sensing elements
41 monocrystalline silicon-metal fever couple group
411 monocrystalline silicon-metal fever couple
4111 metal thermocouple arms
4112 monocrystalline silicon thermocouple arms
5 ambient resistance elements
6 lead pad
7 second medium films
71 second medium membrane layers
8 second grooves
S1~S7 step
Specific embodiment
Illustrate embodiments of the present invention below by way of specific specific example, those skilled in the art can be by this specification
Other advantages and efficacy of the present invention can be easily understood for disclosed content.The present invention can also pass through in addition different specific realities
The mode of applying is embodied or practiced, the various details in this specification can also based on different viewpoints and application, without departing from
Various modifications or alterations are carried out under spirit of the invention.
Fig. 1 is please referred to Figure 15.It should be noted that diagram provided in the present embodiment only illustrates this in a schematic way
The basic conception of invention, though only show in diagram with related component in the present invention rather than package count when according to actual implementation
Mesh, shape and size are drawn, when actual implementation form, quantity and the ratio of each component can arbitrarily change for one kind, and its
Assembly layout form may also be increasingly complex.
As shown in Figure 1, Figure 2 and shown in Figure 14, the present invention provides a kind of thermoelectric pile formula gas flow sensor, comprising:
Substrate 1, has a groove 11, and the groove 11 is opened in the upper surface of the substrate 1；
First medium film 2 is covered in 11 top of groove, and is connected with the substrate 1, the first medium film 2
A heat-insulated cavity is surrounded jointly with the substrate 1；
Heating element 3 is located at 2 surface of first medium film；And
At least two sensing elements 4 are located on the first medium film 2, and are set to the two sides of the heating element 3,
The sensing element includes at least one set of monocrystalline silicon-metal fever couple group 41, if the monocrystalline silicon-metal fever couple group 41 includes
Dry monocrystalline silicon-metal fever couple 411.
Specifically, in the present embodiment, the heating element 3 can be adding thermal resistance, the sensing element 4 is located at described
The two sides of heating element 3, the i.e. position of upstream and downstream separately constitute the independent thermoelectric pile detection circuit in upstream and downstream two.Wherein,
The monocrystalline silicon-metal fever couple group 41 can for one group or two or more sets, depending on actual demand, when monocrystalline silicon-gold
Belong to thermocouple to when group 41 is two or more sets, the first connection of the monocrystalline silicon-metal fever couple group 41 constitutes complete detection line
Road.Further, the monocrystalline silicon-metal fever couple group 41 may include any monocrystalline silicon-metal fever couple 411, such as 2~
It 100, depending on actual demand, is not particularly limited herein, 7 is selected as in the present embodiment.
Specifically, 1.3 μm of 518 μ m of size, 350 μ m of the first medium film 2, and the heat-insulated cavity constituted
Depth is 40~60 μm, and preferably 50 μm, the monocrystalline silicon-metal fever couple is formed using p type single crystal silicon-gold metal material,
The independent thermoelectric pile in upstream and downstream two is by 21 pairs of thermocouples to forming, and wherein thermocouple is 100~180 μm to length, preferably
144 μm, width be 1~5 μm, preferably 3 μm, with a thickness of 0.1~0.8 μm, preferably 0.3 μm, the overall length of the heating element
Degree be 300~380 μm, preferably 340 μm, width be 8~12 μm, preferably 10 μm, with a thickness of 0.1~0.5 μm, preferably
0.3μm。
In addition, the setting of the heat-insulated cavity of the thermoelectric pile formula gas flow sensor of the application make the heating element and
The sensing element vacantly with the substrate, reduces the silicon body heat dissipation of the application, in the present embodiment, the heating unit completely
Part is adding thermal resistance, and the sensing element includes p type single crystal silicon-gold metal fever couple.
As an example, the first medium film 2 includes several trench structures 21 for running through its upper and lower surface, the groove profile
Structure 21 and the monocrystalline silicon-metal fever couple group 41 are arranged in parallel and alternate intervals are arranged.
Specifically, the trench structure 21 makes between the adjacent monocrystalline silicon-metal fever couple group 41 and the monocrystalline
Silicon-metal thermocouple is physically separated between group 41 and the substrate 1, that is to say, that each monocrystalline silicon-metal fever couple group 41
The corresponding first medium film 2 is spaced apart from each other, and Jie of the monocrystalline silicon-metal fever couple group 41 first is arranged
Plasma membrane and be not provided with thermocouple be also to the first medium membrane part of group it is separated from each other, be also achieved that the monocrystalline silicon-metal
Thermocouple is to 41 and the physical isolation of substrate, so as to prevent heat from transmitting between deielectric-coating, that is to say, that make the sensing
Each monocrystalline silicon-thermocouple of element 4 is isolated by air completely between group 41, thus reduce the silicon body heat dissipation of the application,
Improve the performance of sensor.In addition, the trench structure 21 can also be set to the heating element and the sensing element
Between the first medium film on, to both make to be isolated by air, reduce thermal losses.
As an example, the monocrystalline silicon-metal fever couple 411 includes monocrystalline silicon thermocouple arm 4112 and metal thermocouple arm
4111, the monocrystalline silicon thermocouple arm 4112 is located at surface of the first medium film 2 close to 11 side of groove, the metal
Thermocouple arm 4111 includes vertical component effect and horizontal part, and the vertical component effect is through the first medium film 2 and the monocrystalline silicon thermocouple arm
4111 are connected, and the horizontal part is connected with the vertical component effect and is located at the first medium film 2 far from the groove side
Surface.
As an example, the heating element 3 is located at the first medium film 2 close to the surface of 11 side of groove.
Specifically, in the present embodiment, it is described in the heating element 3 and the monocrystalline silicon-metal fever couple 411
Monocrystalline silicon thermocouple arm 4112 is located at the same side of the first medium film 2, and the metal thermocouple arm 4111 is located at and the two phase
Pair the first medium film 2 the other side, the heating element 3 is located at described first with the monocrystalline silicon thermocouple arm 4112 and is situated between
Plasma membrane 2 it is ipsilateral, and be located at close to the groove 11 side, advantageously reduce thermal losses, be further ensured that thermoelectric pile formula gas
The sensitivity of body flow sensor improves device performance.In addition, the arm of monocrystalline silicon thermocouple described in the present embodiment can be inhomogeneity
The monocrystalline silicon of type doping, the metal thermocouple arm may be the various metal materials such as Pt, Ni, Au, Al, Cu, does not do have herein
Body limitation.
As an example, the substrate 1 is (111) monocrystalline silicon.
Specifically, the substrate 1 can be monocrystalline silicon, polysilicon, metal liner is low, organic lining is low, PCB serves as a contrast low various linings
Low material may further be in the present embodiment the list of (111) crystal face of N-type (or p-type) using (111) monocrystalline substrate
The silicon wafer of face (or two-sided) polishing can improve many defects of traditional silicon wafer (such as (100) silicon wafer), such as by (100) silicon
Piece wet etching characteristic is it is found that medium membrane area and monocrystalline silicon backside mask open areas ratio very little, silicon wafer thickness are got over
Greatly, chip size is bigger, and cost is higher, and the girder structure where the heating element and the temperature-sensitive element needs edge
(110) the certain angle of crystal orientation deflection is just able to achieve the release of girder construction wet etching, and it is fixed which results in sensor subsequent installations
Bit comparison is difficult.
As an example, the heating element 3 is arranged along<110>crystal orientation, the monocrystalline silicon-metal fever couple 411 is along<211>
Crystal orientation arrangement.
Specifically, the design of the first medium film unit of the invention, makes heating element 3 arrange along<110>crystal orientation,
The monocrystalline silicon-metal fever couple 411 is set to arrange along<211>crystal orientation, to ensure that device architecture of the invention is adapted to
The diminution of size ensure that the performance of sensor.In addition, the preferably described sensing element 4 is in the heating element in the present embodiment
3 two sides are uniformly and symmetrically distributed, and ensure that being uniformly distributed for the thermal field of sensor in use, further improve gas stream
The detection performance of quantity sensor.
As an example, the first medium film 2 includes the TEOS passivation layer 222 and silicon nitride layer being sequentially stacked from bottom to top
221, it further include oxide layer between the first medium film and the substrate.
As an example, further including second medium film 7, the second medium film 7 is covered in the monocrystalline silicon-metal fever couple
The upper surface of group 41 and its surrounding first medium film 2, for protecting the monocrystalline silicon-metal fever couple.
Specifically, the first medium film includes the TEOS passivation layer 222 of low stress and the silicon nitride layer 221 of low stress,
Wherein, the TEOS passivation layer is low stress TEOS (ethyl orthosilicate, Si (OC2H5)4) passivation layer.In addition, when to the application's
Define heating element and sensing element area substrate annealed after, further include be formed in the first medium film with it is described
Oxide layer 13 between substrate, in other embodiments, the formation process of the oxide layer is not limited to annealing process, may be used also
Think the techniques such as deposition.
Specifically, further include that the peripheral second medium film 7 of the sensing element 4 is set in the present embodiment, described second
Deielectric-coating 7 can be silicon dioxide layer of protection, be also possible to silicon nitride film, silica and silicon nitride composite membrane, organic film
Etc. the various thin-film materials with insulation characterisitic, the purpose is to first medium film jointly by the part monocrystalline silicon-metal fever
Couple cladding, to protect all metallic resistance structures not influenced by the external world, to increase the long-time stability and reliability of device.
As an example, further including several lead pad 6, it is located on the substrate 1, and be set to the heating element 3
And the both ends of each sensing element 4.
As an example, further including ambient resistance element 5, it is set on the substrate 1.
As an example, the ambient resistance element 5, the heating element 3 and the monocrystalline silicon-metal fever couple 411
In monocrystalline silicon thermocouple arm 4112 be boron doped monocrystalline silicon.
Specifically, the temperature of environment can directly utilize the ambient resistance member the invention also includes ambient resistance element 5
Part 5 is directly measured and is compensated, so as to eliminate influence of the gas temperature fluctuation to measurement result, to improve flow detection
Precision.Preferably, the ambient resistance element is arranged along<110>crystal orientation.In addition, the ambient resistance element 5, the heating unit
Monocrystalline silicon thermocouple arm 4112 in part 3 and the monocrystalline silicon-metal fever couple 411 is preferably dense boron doping, further to mention
High device performance.
As shown in Fig. 1~15, the present invention also provides a kind of preparation method of thermoelectric pile formula gas flow sensor, the systems
Preparation Method is the preparation method of the thermoelectric pile formula gas flow sensor of the present invention provided, is included the following steps:
As shown in the S1 in Fig. 3~4 and Figure 15,1) substrate 1 is provided, and in defining heating element on the substrate 1
Area and at least two sensing element areas, the sensing element area are located at heating element area two sides, and including at least one
Monocrystalline silicon-metal fever couple group area, the monocrystalline silicon-metal fever couple group area include several monocrystalline silicon-metal fever couple area；
Specifically, the heating element area is used to form heating element 3, the sensing element area is used to form sensing element
4, the sensing element 4 is located at the two sides of the heating element 3, the i.e. position of upstream and downstream, separately constitutes the independence of upstream and downstream two
Thermoelectric pile detection circuit.The monocrystalline silicon-metal fever couple group 41 can for one group or two or more sets, according to actual demand
Depending on, when monocrystalline silicon-metal fever couple group 41 is two or more sets, the first connection of the monocrystalline silicon-metal fever couple group 41,
Constitute the detection route completed.Further, the monocrystalline silicon-metal fever couple group 41 may include any monocrystalline silicon-metal
Thermocouple depending on actual demand, is not particularly limited herein to 411, such as 2~100,7 is selected as in the present embodiment.
As an example, the substrate 1 is (111) monocrystalline silicon.
Specifically, the thickness of the substrate 1 can be 350~500 μm, preferably 430 μm, axis is cut to 0 ± (0.01 partially
~0.5) °, preferably 0 ± 0.1 °.The substrate 1 can be monocrystalline silicon, polysilicon, metal liner is low, organic lining is low, PCB lining is low
Material low etc. various linings may further be in the present embodiment (111) of N-type (or p-type) using (111) monocrystalline substrate
The silicon wafer of single side (or two-sided) polishing of crystal face, can improve many defects of traditional silicon wafer (as (100) silicon wafer), such as by
(100) silicon wafer wet etching characteristic is it is found that medium membrane area and monocrystalline silicon backside mask open areas ratio very little, silicon wafer
Thickness is bigger, and chip size is bigger, and cost is higher, and the girder structure where the heating element and the temperature-sensitive element needs
The release of girder construction wet etching is just able to achieve along the certain angle of (110) crystal orientation deflection, which results in the subsequent peaces of sensor
Set bit comparison difficulty.
As an example, further including carrying out boron to the heating element area and the sensing element area to mix after step 1)
Miscellaneous step.
As an example, further including the steps that annealing to the structure after boron doping after carrying out the boron doping technique.
Specifically, the method for defining the heating element area and the sensing element area are as follows: 1 surface heat of Yu Suoshu substrate
The certain thickness oxide layer of oxygen simultaneously forms a layer photoresist layer, forms the area to be defined in Yu Suoshu oxide layer and photoresist layer
The opening in domain carries out ion implanting by the opening, in the present embodiment preferably dense boron doping, implantation dosage 5e15cm2
~15e15cm2, preferably 9e15cm2, Implantation Energy is 20~70Kev, preferably 50Kev, is filled with the boron ion note of boron ion
Enter region 12 be it is subsequent to form heating element, monocrystalline silicon-metal thermocouple arm region, furthermore it is also possible to include subsequent
Ambient resistance element area.
Further, the present embodiment further includes the steps that annealing to boron-doped structure, and annealing time is about 1.5~
2.5h, preferably 2h, annealing rear surface grow layer of oxide layer 13, the oxide layer with a thickness of 4000~6000 angstroms, this reality
Apply in example, the oxide layer with a thickness of 5000 angstroms, be further ensured that the stability of device, as shown in Figure 4.
As shown in the S2 in Fig. 5 and Figure 15, step 2) is carried out, etches the substrate to form first groove 14, for fixed
Justice goes out heating element 3 and monocrystalline silicon-metal fever couple 411 position and height；
Specifically, the effect of the first groove 14 is for limiting heating element 3 and monocrystalline silicon-metal fever couple
411, by taking the monocrystalline silicon-metal fever couple 411 as an example, the first groove 14 is set to the subsequent monocrystalline to be formed
Silicon-metal thermocouple to 411 two sides, filler as expendable material, in subsequent etching process, in the first groove
It can be corroded, then remain the part namely monocrystalline silicon-metal fever couple 411 part of its two sides.Further, depth
For limiting the degree in successive substrates corrosion process, and then limit monocrystalline silicon-metal fever couple 411 thickness.
As shown in the S3 in Fig. 6~8 and Figure 15, step 3) is carried out, 14 side wall of Yu Suoshu first groove forms side wall protection
Layer 141, and in deposited sacrificial layer 142 in the first groove 14 for be formed with the side wall protective layer；
As an example, the side wall of Yu Suoshu first groove 14 forms the specific steps of side wall protective layer 141 in step 3)
Are as follows:
3-1) the body structure surface deposited sidewalls protected material bed of material obtained in step 2), the side-wall material protective layer include certainly
The TEOS layer 1411 and silicon nitride layer 1412 being sequentially depositing on down；
3-2) remove the side wall protected material bed of material on 14 bottom of first groove and the surrounding substrate 1
1411,1412, to form the side wall protective layer 141 for being located at 14 side wall of first groove.
Specifically, the sacrificial layer 142 includes but is not limited to polysilicon layer, depositing operation can include but is not limited to oxygen
Change, low-pressure chemical vapor deposition (LPCVD), plasma reinforced chemical vapour deposition (PECVD) etc., the side wall protective layer 141
And the sacrificial layer 142 is used to be corroded in the successive substrates corrosion the step of, play the protection heating element 3 with
And the effect of monocrystalline silicon-metal fever couple 411, further, the silicon nitride layer 1411 with a thickness of 1000~3000 angstroms, it is described
TEOS layer 1411 with a thickness of 1000~3000 angstroms, in the present embodiment, the silicon nitride layer 1412 with a thickness of 2000 angstroms, it is described
TEOS layer 1411 with a thickness of 2000 angstroms.
As shown in the S4 in Fig. 9~10 and Figure 15, step 4) is carried out, in the obtained body structure surface deposition first of step 3)
Medium membrane layers 22, and the first medium membrane layers 22 are etched to exposing the corresponding substrate area of the heating element
To form heating element connecting hole, and expose the corresponding substrate of monocrystalline silicon thermocouple arm in the monocrystalline silicon-metal fever couple
Region is to form monocrystalline silicon thermocouple arm connecting hole 23；
Specifically, the first medium membrane layers 22 are used to be used as support membrane comprising be sequentially depositing from bottom to top
TEOS layers and silicon nitride layer, wherein described TEOS layers with a thickness of 1000~3000 angstroms, the silicon nitride layer with a thickness of
7000~9000 angstroms, in the present embodiment, described TEOS layers with a thickness of 2000 angstroms, the silicon nitride layer with a thickness of 8000
Angstrom, in addition, the purpose of the step also resides in the connecting hole 23 for preparing metal thermocouple arm, wherein the connection of the metal thermocouple arm
The depth in hole 23 is 1.2~2.5 μm, is in the present embodiment 1.7 μm.In addition, further include to be formed heating element connecting hole and
The step of ambient resistance element connecting hole, for drawing heating element and ambient resistance element to realize electrical connection.
In addition, further including after the substrate for defining heating element and sensing element area to the application is annealed
The oxide layer 13 being formed between the first medium film and the substrate, the oxide layer with a thickness of 4000~6000 angstroms,
In the present embodiment, the oxide layer with a thickness of 5000 angstroms.In other embodiments, the formation process of the oxide layer not office
It is limited to annealing process, can also be the techniques such as deposition.
As shown in the S5 in Figure 11~12 and Figure 15, step 5) is carried out, is deposited in the surface of the obtained structure of step 4)
Metal layer is simultaneously graphical to its, with the metal thermocouple arm 4111 formed in the monocrystalline silicon-metal fever couple, the metal thermocouple
Arm 4111 includes vertical component effect and horizontal part, and the vertical component effect runs through the first medium membrane layers 22, the horizontal part and institute
Vertical component effect is stated to be connected and be located at 22 surface of first medium membrane layers；
Specifically, depositing the metal layer includes depositing one layer Cr layers first, one layer of metal is deposited on the Cr layer
The step of material (such as Au), wherein Cr layers with a thickness of 100~500 angstroms, Au layers with a thickness of 3000~8000 angstroms, preferably
5000 angstroms.In addition, the patterning process includes but is not limited to ion beam (Ionbeam) dry etching, the metal layer is formed
Technique includes but is not limited to sputtering method.
As an example, further including being situated between in the obtained body structure surface deposition second of step 5) between step 5) and step 6)
The step of film material layer 71, the second medium membrane layers 71 are for protecting the sensing element 4.
Specifically, the second medium membrane layers 71 can be silicon dioxide layer of protection, it is also possible to silicon nitride film, two
The various thin-film materials with insulation characterisitic such as silica and silicon nitride composite membrane, organic film, the purpose is to first medium
Film jointly coats the part monocrystalline silicon-metal fever couple, to protect all metallic resistance structures not influenced by the external world, to increase
Add the long-time stability and reliability of device, with a thickness of 1000~5000 angstroms, preferably 3000 angstroms.In addition, described first is situated between
The formation process of film material layer 22 and the second medium membrane layers 71 can include but is not limited to oxidation, low pressure chemical
It is vapor-deposited (LPCVD), plasma reinforced chemical vapour deposition (PECVD), sol gel process, organic material coating solidification work
Skill etc..
Specifically, further including the steps that forming the lead pad 6 in this step, when etching the metal thermocouple arm
Etching is formed together, further includes removing in the lead pad 6 after forming the second medium membrane layers further
The step of material layer, such as can be fallen draw using BOE (Buffered Oxide Etch, buffered oxide etch liquid) solution corrosion
SiO above wire bonding disk area2Passivation layer.
As shown in the S6 in Figure 13 and Figure 15, carry out step 6), etch step 5) obtained structure with formed have it is pre-
If the second groove 8 of depth, the second groove 8 is between the adjacent monocrystalline silicon-metal fever couple group area and/or described
Monocrystalline silicon-is between metal fever couple group area and the substrate；
As an example, the first medium film 2 of release includes several trench structures 21, the groove profile in step 7)
Structure is formed by the second groove 8, and the trench structure 21 is arranged in parallel and replaces with the monocrystalline silicon-metal fever couple group
It is intervally arranged.
Specifically, the second groove 8 is used as the subsequent window for carrying out substrate etching, and also further define described
The depth of the depth of the groove 11 in substrate 1 namely the heat-insulated cavity, meanwhile, the second groove 8 is also as subsequent
Form the groove of the trench structure 21, specific location is between the adjacent monocrystalline silicon-metal fever couple group area or institute
Monocrystalline silicon-is stated between metal fever couple group area and the substrate, i.e., the side in the described sensing element area, can also simultaneously be located at
Upper several positions, depending on actual demand, cross-sectional shape is the biggish square bar of length-width ratio, long side with it is described
Monocrystalline silicon-metal fever couple is in the same direction.
As an example, in step 6), the specific steps for forming the second groove 8 include:
6-1) etch the first medium membrane layers 22 of 8 region of second groove；
6-2) continue to etch predetermined depth along the second groove region, to form the second groove 8.
Specifically, step 6-1) in etching can use reactive ion etching (RIE), wherein step 6-1) and can be with
Form the trench structure 21 being located on the first medium film, step 6-2) in etching can be using deep pasc reaction ion
It etches (Deep-RIE), it is of course also possible to use other etching technics, such as inductive coupling reactive ion etching (ICP), ion beam
Etch the various lithographic techniques such as (IonBeam), wet etching, focused-ion-beam lithography (FIB), laser scanning etching.At other
In embodiment, the groove with predetermined depth once can also etch to be formed.Wherein, just fixed by the etching of step 6-2)
The depth of the groove in justice substrate, i.e., the depth of described second depth namely the heat-insulated cavity can be 40~60
μm, in the present embodiment, preferably 50 μm.Here, " the second groove region " refer to ultimately form it is described
The region of first medium membrane layers corresponding to the position of second groove when second groove and substrate.
In addition, when step 5) obtained body structure surface deposition second medium membrane layers 71, step 4-1) quarter
Second medium membrane layers have also been etched away while etching eating away first medium membrane layers.
As shown in the S7 in Figure 14 and Figure 15, step 7) is carried out, is to be served as a contrast described in window erodable section with the second groove 8
Bottom forms heat-insulated cavity, to discharge the first medium film 2 and the monocrystalline silicon thermocouple arm 4112, wherein the first medium
Film 2 is connected with the substrate 1, and surrounds the heat-insulated cavity jointly with the substrate 1, the monocrystalline silicon thermocouple arm 4112 with
The metal thermocouple arm 4111 constitutes the monocrystalline silicon-metal fever couple 411, and forms sensing element 4.
As an example, substrate described in step 1) is (111) monocrystalline silicon, etchant solution employed in step 7) is tetramethyl
Base Dilute Ammonia Solution.
Specifically, in other embodiments, MEMS bulk silicon etching technology can also be potassium hydroxide (KOH) solution corrosion,
The various silicon materials corrosion technologies such as xenon fluoride (XeF).
In addition, further include laser scribing after the above step is finished, the step of with device architecture needed for obtaining.
In conclusion the present invention provides a kind of thermoelectric pile formula gas flow sensor and preparation method thereof, comprising: substrate,
With a groove, the groove is opened in the upper surface of the substrate；First medium film is covered in above the groove, and with
The substrate is connected, and the first medium film and the substrate surround a heat-insulated cavity jointly；Heating element is located at described
First medium film surface；And at least two sensing elements, it is located on the first medium film, and be set to the heating element
Two sides, the sensing element includes at least one set of monocrystalline silicon-metal fever couple group, the monocrystalline silicon-metal fever couple group packet
Include several monocrystalline silicon-metal fever couple.Through the above scheme, the single-chip that the present invention passes through cleverly structure design and innovation
Single side manufacturing technology processes the highest p type single crystal silicon of Seebeck coefficient-gold thermocouple pair on common (111) monocrystalline silicon piece；This
The thermoelectric pile formula gas flow sensor of invention by thermocouple pair and heating element by be located at the heat-insulated cavity immediately below it with
Substrate isolation, utmostly reduces the heat dissipation of adding thermal resistance, substantially increases the detection sensitivity of sensor；Of the invention
Entire flow sensor is all to carry out processing and fabricating from the same surface of monocrystalline silicon piece, therefore chip size is small, at low cost, is suitable for
Produce in enormous quantities.So the present invention effectively overcomes various shortcoming in the prior art and has high industrial utilization value.
The above-described embodiments merely illustrate the principles and effects of the present invention, and is not intended to limit the present invention.It is any ripe
The personage for knowing this technology all without departing from the spirit and scope of the present invention, carries out modifications and changes to above-described embodiment.Cause
This, institute is complete without departing from the spirit and technical ideas disclosed in the present invention by those of ordinary skill in the art such as
At all equivalent modifications or change, should be covered by the claims of the present invention.
Claims (17)
1. a kind of thermoelectric pile formula gas flow sensor characterized by comprising
Substrate, has a groove, and the groove is opened in the upper surface of the substrate；
First medium film is covered in above the groove, and is connected with the substrate, the first medium film and the substrate
A heat-insulated cavity is surrounded jointly；
Heating element, positioned at the first medium film close to the surface of the groove side；And
At least two sensing elements are located on the first medium film, and are set to the two sides of the heating element, the sensing
Element includes at least one set of monocrystalline silicon-metal fever couple group, and the monocrystalline silicon-metal fever couple group includes several monocrystalline silicon-
Metal fever couple；Wherein, the monocrystalline silicon-metal fever couple includes monocrystalline silicon thermocouple arm and metal thermocouple arm, the monocrystalline silicon
Thermocouple arm is located at the first medium film close to the surface of the groove side, and the metal thermocouple arm includes vertical component effect and level
Portion, the vertical component effect are connected through the first medium film with the monocrystalline silicon thermocouple arm, the horizontal part with it is described vertical
Portion is connected and is located at surface of the first medium film far from the groove side.
2. thermoelectric pile formula gas flow sensor according to claim 1, which is characterized in that the first medium film includes
Several run through the trench structure of its upper and lower surface, and the trench structure is arranged in parallel with the monocrystalline silicon-metal fever couple group
And alternate intervals are arranged.
3. thermoelectric pile formula gas flow sensor according to claim 1, which is characterized in that the substrate is that (111) are single
Crystal silicon.
4. thermoelectric pile formula gas flow sensor according to claim 1, which is characterized in that the first medium film includes
The TEOS passivation layer and silicon nitride being sequentially stacked from bottom to top further include oxidation between the first medium film and the substrate
Layer.
5. thermoelectric pile formula gas flow sensor according to claim 1, which is characterized in that the heating element is along < 110
The arrangement of>crystal orientation, the monocrystalline silicon-metal fever couple are arranged along<211>crystal orientation.
6. thermoelectric pile formula gas flow sensor according to claim 1, which is characterized in that it further include second medium film,
The second medium film is covered in the upper surface of the monocrystalline silicon-metal fever couple group and the surrounding first medium film,
For protecting the monocrystalline silicon-metal fever couple.
7. thermoelectric pile formula gas flow sensor according to claim 1, which is characterized in that further include the weldering of several leads
Disk is located on the substrate, and is set to the both ends of the heating element and each sensing element.
8. thermoelectric pile formula gas flow sensor according to any one of claims 1 to 7, which is characterized in that further include
Ambient resistance element is set on the substrate.
9. thermoelectric pile formula gas flow sensor according to claim 8, which is characterized in that the ambient resistance element,
Monocrystalline silicon thermocouple arm in the heating element and the monocrystalline silicon-metal fever couple is boron doped monocrystalline silicon.
10. a kind of preparation method of thermoelectric pile formula gas flow sensor, which comprises the steps of:
1) substrate is provided, and in defining heating element area and at least two sensing element areas, the sense on the substrate
It surveys element region and is located at heating element area two sides, and including at least one monocrystalline silicon-metal fever couple group area, the monocrystalline
Silicon-metal thermocouple includes several monocrystalline silicon-metal fever couple area to a group area；
2) substrate is etched to form first groove, for defining in heating element and monocrystalline silicon-metal fever couple
Position and thickness where monocrystalline silicon thermocouple arm；
3) Yu Suoshu first groove side wall forms side wall protective layer, and in the first groove for being formed with the side wall protective layer
Interior deposited sacrificial layer；
4) first medium membrane layers are deposited in the obtained body structure surface of step 3), and etches the first medium membrane layers
To exposing the corresponding substrate area of the heating element to form heating element connecting hole, and expose the monocrystalline silicon-gold
Belong to the corresponding substrate area of monocrystalline silicon thermocouple arm of thermocouple centering to form monocrystalline silicon thermocouple arm connecting hole；
5) in the surface deposited metal layer of the obtained structure of step 4) and to its it is graphical, to form the monocrystalline silicon-metal
The metal thermocouple arm of thermocouple centering, the metal thermocouple arm include vertical component effect and horizontal part, and the vertical component effect runs through described first
Medium membrane layers, the horizontal part are connected with the vertical component effect and are located at first medium membrane layers surface；
6) etch step 5) to form second groove, the second groove is located at the adjacent monocrystalline silicon-metal for obtained structure
Thermocouple is between group area and/or the monocrystalline silicon-is between metal fever couple group area and the substrate；
7) form heat-insulated cavity by substrate described in window erodable section of the second groove, with discharge the first medium film and
The monocrystalline silicon thermocouple arm, wherein the first medium film is connected with the substrate, and surrounds jointly with the substrate described
Heat-insulated cavity, the monocrystalline silicon thermocouple arm and the metal thermocouple arm constitute the monocrystalline silicon-metal fever couple, and form sensing
Element.
11. the preparation method of thermoelectric pile formula gas flow sensor according to claim 10, which is characterized in that step 1)
With between step 2), further include that boron doped step is carried out to the heating element area and the sensing element area.
12. the preparation method of thermoelectric pile formula gas flow sensor according to claim 11, which is characterized in that carry out institute
After stating boron doping technique, further include the steps that annealing to the structure after boron doping.
13. the preparation method of thermoelectric pile formula gas flow sensor according to claim 10, which is characterized in that step 3)
In, the side wall of Yu Suoshu first groove forms the specific steps of side wall protective layer are as follows:
3-1) the body structure surface deposited sidewalls protected material bed of material obtained in step 2), the side-wall material protective layer include from lower and
On the TEOS layer and silicon nitride layer that are sequentially depositing；
The side wall protected material bed of material on the first groove bottom and the surrounding substrate is removed, 3-2) to form position
In the side wall protective layer of the first groove side wall.
14. the preparation method of thermoelectric pile formula gas flow sensor according to claim 10, which is characterized in that step 5)
With between step 6), further include the steps that in step 5) obtained body structure surface deposition second medium membrane layers, described the
Second medium membrane layers are for protecting the sensing element.
15. the preparation method of thermoelectric pile formula gas flow sensor according to claim 10, which is characterized in that step 6)
In, the specific steps for forming the second groove include:
6-1) etch the first medium membrane layers of the second groove region；
6-2) continue to etch predetermined depth along the second groove region, to form the second groove.
16. the preparation method of thermoelectric pile formula gas flow sensor according to claim 10, which is characterized in that step 1)
Described in substrate be (111) monocrystalline silicon, etchant solution employed in step 7) is tetramethyl Dilute Ammonia Solution.
17. the preparation method of thermoelectric pile formula gas flow sensor described in any one of 0~16 according to claim 1, special
Sign is, in step 7), the first medium film of release includes several trench structures, wherein the trench structure is by institute
It states second groove to be formed, the trench structure is arranged in parallel with the monocrystalline silicon-metal fever couple group and alternate intervals are arranged.
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| CN109613085A (en) * | 2018-12-12 | 2019-04-12 | 中国电子科技集团公司第四十九研究所 | One kind being based on the gas sensitization chip array and preparation method thereof of [111] monocrystalline silicon |
| CN112484800B (en) * | 2020-11-24 | 2022-02-22 | 中国科学院上海微系统与信息技术研究所 | Thermal reactor type gas mass flow sensor and preparation method thereof |
| CN214748202U (en) * | 2021-02-09 | 2021-11-16 | 青岛芯笙微纳电子科技有限公司 | High-sensitivity MEMS flow sensor |
| CN113049053B (en) * | 2021-03-15 | 2022-12-30 | 青岛芯笙微纳电子科技有限公司 | High-performance MEMS flow sensor and preparation method thereof |
| CN113175963B (en) * | 2021-04-27 | 2022-10-28 | 华东师范大学 | MEMS flow sensor and preparation method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4501144A (en) * | 1982-09-30 | 1985-02-26 | Honeywell Inc. | Flow sensor |
| CN1501059A (en) * | 2002-11-15 | 2004-06-02 | 欧姆龙株式会社 | Flow sensor and flow rate measuring method |
| US20050049805A1 (en) * | 2003-08-28 | 2005-03-03 | Ulrich Bonne | Methods and systems for temperature compensation of physical property sensors |
| CN1650175A (en) * | 2002-05-02 | 2005-08-03 | 株式会社山武 | Flow velocity sensor |
| CN101443635A (en) * | 2006-03-10 | 2009-05-27 | 霍尼韦尔国际公司 | Thermal mass gas flow sensor and method of forming same |
| US7908096B2 (en) * | 2007-09-28 | 2011-03-15 | Siargo Ltd. | Integrated micromachined thermal mass flow sensor and methods of making the same |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11148944A (en) * | 1997-11-18 | 1999-06-02 | Yamatake Corp | Flow velocity sensor and flow velocity-measuring apparatus |
-
2017
- 2017-07-06 CN CN201710548160.3A patent/CN107328449B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4501144A (en) * | 1982-09-30 | 1985-02-26 | Honeywell Inc. | Flow sensor |
| CN1650175A (en) * | 2002-05-02 | 2005-08-03 | 株式会社山武 | Flow velocity sensor |
| CN1501059A (en) * | 2002-11-15 | 2004-06-02 | 欧姆龙株式会社 | Flow sensor and flow rate measuring method |
| US20050049805A1 (en) * | 2003-08-28 | 2005-03-03 | Ulrich Bonne | Methods and systems for temperature compensation of physical property sensors |
| CN101443635A (en) * | 2006-03-10 | 2009-05-27 | 霍尼韦尔国际公司 | Thermal mass gas flow sensor and method of forming same |
| US7908096B2 (en) * | 2007-09-28 | 2011-03-15 | Siargo Ltd. | Integrated micromachined thermal mass flow sensor and methods of making the same |
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