CN1297802C - All silicon integrated flow sensor and method for manufacturing the same - Google Patents
All silicon integrated flow sensor and method for manufacturing the same Download PDFInfo
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- CN1297802C CN1297802C CNB2004100391393A CN200410039139A CN1297802C CN 1297802 C CN1297802 C CN 1297802C CN B2004100391393 A CNB2004100391393 A CN B2004100391393A CN 200410039139 A CN200410039139 A CN 200410039139A CN 1297802 C CN1297802 C CN 1297802C
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Abstract
The present invention provides an all-silicon integrated flow transducer and a manufacturing method thereof. The integrated flow transducer comprises a silicon monocrystal substrate embedded with a porous monocrystal silicon trap in which two sets of thermal couple stacks are arranged and composed of a plurality of n-type doped monocrystal silicon strips matched in pairs with p-doped polysilicon strips, p-type doped polysilicon heating elements, p-type doped polysilicon temperature test elements and an amorphous silicon carbide passivating layer. The porous monocrystal silicon trap provides a heat isolation base for the heating elements so as to build a large temperature gradient with low power consumption. The highly sensitive thermal couple stacks are used for detecting the temperature gradient variation caused by varied mean flow rate. The main elements of the device are made of silicon, so the all-silicon integrated flow transducer can be made with a pure integrated circuit technique, which is suitable for large-scale production and beneficial for reducing cost.
Description
Technical field
The invention relates to integrated flow sensors, about being temperature detection unit with silicon thermocouple heap, is hot isolated base with the porous monocrystalline silicon trap particularly, and is the integrated flow sensors of main saw lumber with silicon.
Background technology
The application of flow sensor is very widely.Industrial natural G﹠W all need be used flow sensor instrumentation supply, and charges thus.In auto industry, flow sensor also is crucial sensing element, the control of engine and discharging, and flowing and consuming of oil plant all do not left it.In addition, environment protection control, bio-instruments, air-conditioning system, petrochemical complex etc. also all are the flow sensor application places.
The advantage that with the integrated circuit technique is the integrated flow sensors that gets up of base growth is conspicuous, and these advantages mainly are to be fit to large-scale production, thereby with low cost, combine with signal processing circuit easily, thereby excellent performance.
The not too big difference of the principle of work of integrated flow sensors and traditional flow sensor, it also is the part heat that is sent by fluid removal sensor heating unit, and produce thermograde at its periphery, measure the temperature difference of regional area by sensor thermometric unit, can extrapolate the average velocity that fluid flows through.
The design of integrated flow sensors, substantially based on two kinds of considerations, the one, reduce the thermal conductance loss of heating unit as possible, highlighting the heat transfer effect of fluid, the 2nd, improve the sensitivity of thermometric unit as possible, so that measure variation of temperature in less adding under the heat power consumption.
Design under the former considers to guide is to use micro-fabrication technology to form the cavity that hollows out in silicon chip, and fabric medium membrane bridge above it.The shortcoming of this design is that structural strength is poor, and the solia particle that mixes in fluid is damaged under impacting easily.
Design under the latter considers to guide is to do thermometric unit with integrated thermocouple heap, such as aluminium/polysilicon thermocouple heap is just used often.But as in conjunction with adopting the dielectric film bridge, the problem of bad mechanical strength is also unresolved.If directly be produced on the silicon chip that covers with general silicon oxide layer, because its thermal conductance is excessive, the advantage that makes the thermocouple heap be had is difficult to manifest.
Purpose of the present invention, all things considered are exactly to propose a scheme that comprehensively solves for the problem that exists in the above-mentioned integrated flow sensors.To be achieved as follows target exactly particularly: the one, use the high thermoelectric material of matching Bake (Seebeck) coefficient as far as possible, the thermocouple that has higher conversion efficiency of thermoelectric with formation is piled, thus the variation that is able under the situation of low heating power consumption, measure the mobile less thermograde that causes of fluid; Two are to use and need not the bottom and hollow out, and thicker low thermal conductance material layer is hot heat insulation support base, replacing the film micro-bridge supporting structure of fragility, thereby make sensor be stood the fluid impact of filtered; The 3rd, get rid of the procedure of processing of little manufacturing, make sensor with more simple integrated circuit technique, thereby simplify manufacture process, exempt demand to specific installation, reduce production costs largely.
Someone measures by pair thermoelectric material that forms thermocouple with platinum pairing widely, and cool knot is in 0 degree centigrade during measurement, and thermojunction is in 100 degrees centigrade.Measurement result shows, n-shape silicon reaches as high as 450 microvolts (voltage)/every degree (temperature) with respect to the Seebeck coefficient of platinum, only be lower than n-type germanium, the 548 microvolt voltages that its Seebeck coefficient reaches as high as/every degree centigrade, the Seebeck coefficient of p-type silicon reaches as high as 450 microvolt voltages/every degree centigrade, is in most significant digit in all known p-type thermoelectric materials.
But silicon materials also are good heat conductors, and this has but limited silicon thermocouple heap and directly has been formed at the interior possibility of silicon body, the loss that causes because the type of thermal communication between the cool thermojunction that is difficult to reduction silicon thermocouple crosses the transmission of silicon body.This loss hinders between two knots sets up the enough big temperature difference, thereby is difficult to obtain enough big electric signal.
Summary of the invention
The present invention uses anodizing technology in order to break away from this predicament, optionally forms the porous monocrystalline silicon trap in silicon monocrystalline substrate, thereby is able to form from silicon substrate the monocrystalline silicon strip that porous monocrystalline silicon centered on by extremely low thermal conductance.The monocrystalline silicon strip of isolating with this heat is made the pairing material of sensor thermocouple heap, and then its high Seebeck coefficient advantage is fully utilized, and the shortcoming of its excellence conductor is again eliminating, thereby can the splendid silicon thermocouple heap of obtained performance.
Porous monocrystalline silicon is that silicon single crystal material is through the formed single crystal silicon material that contains a large amount of micropores of anodic oxidation.Porous monocrystalline silicon is easy to high-temperature thermal oxidation and is transformed into oxidized porous silicon, thereby has the human oxidized porous silicon to make the heat insulation support seat of flow sensor.But this high-temperature thermal oxidation porous silicon has very big internal stress, and along with the oxidized porous silicon layer thickness increases, its strain also constantly increases, and can make its surface curvature at last, so that the damage of finally breaking.Therefore thickness that can the actual oxidized porous silicon layer that utilizes is very limited, that is the improvement of its effect of heat insulation neither be clearly.
Measurement shows, the thermal conductivity coefficient of unoxidized porous monocrystalline silicon is usually than low 2 to 3 orders of magnitude of monocrystalline silicon, the thermal conductivity coefficient that is monocrystalline silicon is 156 watts/every meter every degree, and the thermal conductivity coefficient of unoxidized porous monocrystalline silicon is 0.3 to 2.7 watt/every meter every degree, and its minimum is less than 1.1 watts/every meter every degree of thermal conductivity coefficient that is used as the monox of heat-barrier material usually.Measure and show that also just the internal stress of the porous monocrystalline silicon that forms is generally and bears 1,000 ten thousand handkerchiefs, hangs down 2 orders of magnitude than the internal stress of thermal oxidation silicon.The thermal treatment meeting changes the internal stress of porous monocrystalline silicon, and 300 degrees centigrade oxidation processes, its internal stress become positive 2,000 ten thousand MPas.As handling in nitrogen, and temperature is controlled in 450 degrees centigrade, and its internal stress might be reduced to 0.Owing to effect of heat insulation along with thickness strengthens, the present invention adopts the heat of making sensor heating unit through the thick porous monocrystalline silicon layer of this processing to isolate and supports seat, thickness range can be from tens microns to the hundreds of micron.
Though micro-fabrication technology has bigger compatibility with integrated circuit technique, still need increase some special manufacturing equipments actually and set up some special processing technologys.As mentioned above, the thermometric of flow sensor of the present invention unit is silicon thermocouple heap, and heat insulation pedestal is the porous monocrystalline silicon trap, and this main devices unit that just means sensor is all processed by silicon, does not need to implement extra little manufacturing step.The integrated circuit fabrication process major part also is round silicon chip being processed, therefore can being used ripe integrated circuit production line and carry out the production of sensor, to reduce the producing cost of sensor to greatest extent.
Description of drawings
Below the accompanying drawing of total silicon flow sensor of the present invention is done concise and to the point the description.
Fig. 1 is the positive surface construction skeleton view of total silicon flow sensor of the present invention.
The cross-sectional view that Fig. 2 represents for cutting along total silicon flow sensor front surface A A line shown in Figure 1.
The partial cross sectional view that Fig. 3 represents for cutting along the positive BB line of total silicon flow sensor shown in Figure 1.
Fig. 4 is the metering circuit calcspar of total silicon flow sensor of the present invention.
Fig. 5 is the cross-sectional view of total silicon flow sensor of the present invention when forming n-type doped single crystal silicon strip.
Fig. 6 be total silicon flow sensor of the present invention so that cross-sectional view when forming the porous monocrystalline silicon trap.
Fig. 7 be total silicon flow sensor of the present invention so that cross-sectional view when forming device element such as n-type doped polycrystalline silicon strip.
Cross-sectional view when Fig. 8 in the end forms the amorphous carborundum passivation layer for total silicon flow sensor of the present invention.
Embodiment
The complete construction of total silicon integrated flow sensors of the present invention such as Fig. 1, Fig. 2 and shown in Figure 3.What Fig. 1 represented is the positive surface construction of sensor.This shows that the composition of sensor comprises a monocrystalline substrate 101, upstream thermocouple heap 102A and heat radiator 105A thereof, downstream thermocouple heap 102B and heat radiator 105B thereof, heating unit 103, upstream thermometric unit 104, and some press welding blocks 106.Arrow indication among the figure is represented the direction that fluid flows.
Fig. 2 represents is the xsect that the AA line along sensor surface shown in Figure 1 cuts down.This figure shows, embed empty silicon trap 108 more than in the monocrystalline substrate of sensor in 101, embed monocrystalline silicon strip 109A and the 109B that forms the thermocouple heap in the trap, the trap face is furnished with polysilicon strip 111A and the 111B that forms the thermocouple heap, the lower surface of the opposed end of two polysilicon strips directly contacts with monocrystalline silicon strip upper surface and forms centre junction or thermojunction 110A and 110B, most of zone of polysilicon strip and its lower mono-crystalline silicon bar is by 112 layers of isolation of monox, be furnished with the heating unit 103 that isolates by silicon oxide layer 112 between two polysilicon strips, the disposed outside of upstream heat radiator 105A has the upstream thermometric unit 104 by 112 layers of isolation of monox, and all are coated with passivation layer 113 above the device element.
Fig. 3 represents is the part xsect that the BB line along sensor surface shown in Figure 1 cuts down.What this figure will show is the structure of thermocouple heap limit, sensor downstream end, the position, end, limit that is monocrystalline silicon strip 109B and polysilicon strip 114B is all widened towards relative direction, make it form directly contact knot or cold junction 114B, adjacent monocrystalline silicon strip 109B is isolated by porous monocrystalline silicon trap 108, adjacent polysilicon strip 109B is isolated by silicon oxide layer 112, and the top of polysilicon strip 109B covered by passivation layer 113.The structure of thermocouple heap limit, upstream end is identical therewith, and the direct contact knot or the cold junction 114A that form between monocrystalline silicon strip 109A and the polysilicon strip 114A are promptly also arranged, and does not just draw on the figure.
The material of the making heating unit that can select for use has a variety of, is doped polycrystalline silicon but be worth top-priority.The also available a variety of materials of upstream thermometric unit form, but the material of most convenient or polysilicon.Passivating film should preferentially be selected amorphous carborundum for use, because its antiacid alkali corrosion is very competent, can allow sensor stand the test of various rugged surroundings.Also can make substitute with silicon nitride, more universal because of its processing procedure, implement easier.
During the sensor running, must be placed in the pipeline that fluid passes through, make it positive parallel with the working direction of fluid, and its upstream thermocouple heap is in the upstream of fluid, downstream thermocouple heap is in the downstream of fluid, the streamline of fluid vertically passes through the heating unit between upstream thermometric unit and the two thermocouples heap along the length direction of thermocouple heap thermocouple.To the heating unit energising heating of sensor, and keep the stable of heating power, so that near the zone of heating first both sides is warmed up to certain numerical value.If there is not fluid to flow through, the temperature field of sensor surface top should be to successively decrease for middle mind-set both sides to heat unit, but must strictness defer to the rotational symmetry distribution, what the temperature difference that this moment, upstream and downstream thermocouple heap was measured should be the same.
The influence that fluid flows through is that the axis of symmetry downstream of Temperature Distribution is moved.Fluid can be taken away a part of heat energy of the first near zone of heating, and general's a part of thermal energy transfer is wherein given the thermojunction and the cold junction of downstream thermocouple heap, therefore the temperature difference measured of upstream and downstream thermocouple heap can change, and the upstream thermocouple is measured the temperature difference and diminished, and the temperature difference that thermocouple heap in downstream is measured becomes big.The numerical value of this difference variation is relevant with the mean flow rate of fluid, thereby can derive the mean flow rate of fluid according to this measurement.
The electric signal that flow sensor is measured can adopt one-level Sigma-Delta analog to digital converter to handle.One-level Sigma-Delta analog to digital converter is extensively used sensor measuring circuit, and its reason is that circuit structure is simple, the element low price, and noise level is low, plurality of advantages such as power consumption province.
Fig. 4 is the calcspar of this metering circuit embodiment.This circuit mainly comprises the thermocouple heap 201 of flow sensor, prime amplifier 202, a comparer (Comparator) or a quantizer (Quantizer) 204, bidirectional analog switch (Transfergate) 205, low frequency digital wave filter 206, phase inverter (Inverter) 207, NAND gate (NAND) 208, and charge pump or unit digital-to-analog conversion (D/A) device 209 etc.
The thermocouple heap of flow sensor converts the flow velocity change to voltage output.Prime amplifier amplifies this voltage signal, is transported to comparer then.Comparer is made up of the phase inverter of two polyphones, the thermocouple heap signal that is used for relatively amplifying and the feedback signal of converter.The output of comparer encourages charge pump by behind the NAND gate.The bidirectional analog switch plays delayed-action to the output pulse of comparer, and to allow the output pulse be that the capacitor of postposition is stored.
The circuit operation is by the non-overlapped clock signal Φ of two-phase
1And Φ
2Synchronously.(Φ when action I
1Be in low level), transistor P
6Close.(Φ when action II
2Be in low level), the bidirectional analog switch open, the output of comparer is sent to NAND gate.Meanwhile, transistor P
5Open capacitor C
pCharge to the supply voltage value.(Φ when action III
2High), the output of comparer is by the trivial holding capacitor C that deposits
sOn, transistor P meanwhile
5Close.(Φ when action IV
1Raise), if capacitor C
IntOn feedback voltage V
CintBe lower than the thermocouple heap voltage V after the amplification
Th, bias voltage V
bTo be added to transistor P
6The coral utmost point.This moment C
pBy transistor P
6Discharge, a certain amount of electric charge of pumping is to capacitor C
Int, and allow this process repeat down, until voltage V
CintGreater than voltage V
ThTill.The mean value of the clock pulses number of exporting behind the process low frequency digital filter filtering is directly followed the tracks of the output voltage values of thermocouple heap, thereby the analog-signal transitions of thermocouple heap is become the digital signal that can supply microprocessor processes.
The manufacture process of total silicon flow sensor of the present invention such as Fig. 4 are to shown in Figure 7, and what these figure represented is the xsect of chip, and the chip lateral extent just in time comprises the horizontal span of a sensor.
With reference to figure 1, be used for making the monocrystalline substrate 301 that the backing material of sensor mixes for the p-type, its crystal orientation does not have special requirement, its resistivity can from low-resistance to resistance, but had better not surpass 10 ohm-cms.It is to generate the silicon oxide layer 302 of 1 micron thickness at silicon substrate 301 upper surfaces by thermal oxide that processing procedure begins, and advances photoetching corrosion processing then, shelters pattern to form the diffusion window.The diffusion window is long narrow strip, its wide 1-2 micron, long 50-200 micron.Have two groups, every group contains the 12-48 bar, uniformly-spaced is arranged in parallel spacing 2-3 micron.Arrange side by side for two groups, intermediate section is every the 40-60 micron.Silicon oxide layer with patterning carries out n-type doping thermal diffusion for sheltering, and forming sheet resistance in silicon substrate 301 is the monocrystalline silicon diffusion bar 303A and the 303B of the n-type doping of 3-20 ohms/square and thickness 0.5-3 micron.
With reference to figure 5,,, form the silicon nitride layer 304 of thickness 2000-4000 dust in surface of silicon then by low-pressure chemical vapor deposition with the silicon oxide layer 302 on dilute hydrofluoric acid solution erosion removal silicon substrate 301 surfaces.Silicon nitride layer 304 is carried out photoetching corrosion, silicon nitride layer 304 is become comprise the pattern of sheltering of rectangular aperture.The monocrystalline silicon diffusion bar that rectangular aperture must mix two groups of n-types arranges 303A and 303B comprises wherein, arrangement is arranged along long side direction, and the end top, outer end of arranging can flush with edge, long limit, or exceed the 20-30 micron a little forward, the separation distance that keeps the 50-200 micron end to end with the minor face edge of arrangement.
In dense hydrofluoric acid solution, carry out anodic oxidation subsequently, make the p-type monocrystalline silicon region generation anodic oxidation reactions in the rectangular aperture of monox masking layer, be converted into porous monocrystalline silicon trap 305.The hydrofluoric acid solution that anodic oxidation is used contains a 49% hydrofluorite and a absolute ethyl alcohol, and oxidation current density is controlled at 60-80 milliampere/square centimeter.The growth rate of the porous monocrystalline silicon that obtains with this understanding be the 3-4 micron/minute, porosity is 60-80%.
Because anodic oxidation reactions has selectivity to the doping type and the doping content of monocrystalline silicon, and this selectivity can also further be highlighted by the numerical value that qualification applies voltage.Therefore anodic oxidation reactions does not take place in the monocrystalline silicon diffusion bar 303A and the 303B that can keep the n-type to mix in the process that generates p-type porous monocrystalline silicon, can not be transformed into porous monocrystalline silicon yet.Therefore as shown in Figure 5, monocrystalline silicon diffusion bar 303A and 303B are in and are absorbed among the porous monocrystalline silicon trap 305, and its bottom and periphery are all centered on by porous monocrystalline silicon, and itself and silicon substrate are separated.
It is the 40-80 micron that the porous monocrystalline silicon trap that forms requires deeply, and the about 20-40 micron of the width of its lateral magnification towards periphery, whole trap body image are inverted taper platforms.Should be noted that, because the cross growth of porous monocrystalline silicon, the end top, outer end that the n-type doped monocrystalline silicon diffusion bar of this moment is arranged has been in the porous monocrystalline silicon trap, and keeps certain interval with the trap limit, that is the limit end side surface of n-type doped monocrystalline silicon diffusion bar is also centered on by porous monocrystalline silicon.The porous monocrystalline silicon trap surface that generates with the naked eye it seems it should is that light is level and smooth, as not carrying out anodised surface of silicon.
Through anodic oxidation, the thickness of nitride masking film meeting attenuation on the silicon substrate 301, but also residual certain thickness.Must in dilute hydrofluoric acid solution, proceed corrosion, with its thorough removal.At room temperature dry up then, and carry out low thermal oxidation immediately and handle with the silicon chip of nitrogen after with anodic oxidation.Oxidizing temperature is 300 degrees centigrade, and oxidizing atmosphere is dried oxygen, and oxidization time is 1 hour.After this processing of process, the bore area of porous monocrystalline silicon can be given birth to the silicon oxide layer of thick about 20 dusts, and therefore the 2000-5000 dust can be improved than primary plane in the surface of porous monocrystalline silicon trap 305.
With reference to figure 6,, comprise the silicon oxide layer 306 of porous monocrystalline silicon trap 305 surfaces and doped single crystal silicon strip 303A and about 5000 dusts of 303B surface low-temperature chemical vapor deposition thickness on silicon substrate 301 surfaces.And then form p-type doped polysilicon layer with the low temperature chemical vapor deposition technology.The thickness of polysilicon layer is the 0.5-2 micron, and the doping surfaces square resistance is the 5-20 ohms/square.Then polysilicon layer is carried out photoetching corrosion processing, to form the pattern of forming by polysilicon strip.This pattern comprises p-type doped polycrystalline silicon strip 307A and the 307B that constitutes thermopile with n-type doped single crystal silicon strip, the heat radiator 309A and the 309B of two groups of thermocouples, heating unit 310 and thermometric unit 311.As seen from the figure, polysilicon strip covers the monocrystalline silicon strip under it, and the lower surface of its two ends end regions directly contacts thermojunction and the cold junction that forms the thermocouple heap with the corresponding upper surface of monocrystalline silicon strip under it.That can see among the figure has only near heating first thermojunction 308A and 308B, and can show because of not being on the xsect near the cold junction of heat radiator.
With reference to figure 7, advanced row metalization promptly forms metal connecting line and press welding block, thinks that the device element that forms on the silicon substrate comprises the thermocouple heap, the first passage that provides external circuit to be connected with thermometric unit of heating.For this reason, palpus deposited by electron beam evaporation or ion beam sputtering technology form thick about 1 micron metallic film, such as the aluminium film.Carry out photoetching corrosion processing then, form required aluminum strip and aluminium square.Then pushing up and take off (lift-off) technology, promptly form the photoresist pattern earlier, make photoresist only cover the press welding block zone, all must come out in other device element zone.Strengthen the amorphous carborundum layer that gas phase deposition technology forms thick 2000-5000 dust with ion beam then.Remove photoresist in the lysate of photoresist, thereby remove the amorphous carborundum layer on the press welding block zone, the zone of other no photoresist all is coated with the amorphous carborundum layer.So far whole chip manufacturing proces of total silicon flow sensor of the present invention have just been finished.
Above-mentioned explanation is only limited to basic structure and the embodiment of setting forth total silicon flow sensor of the present invention.Under the guidance of this explanation, those skilled in the art are easy to carry out the part replenish, and revise and adjust, but all also in the related scope of claim of the present invention.
Claims (11)
1. total silicon integrated flow sensors is characterized in that this sensor is formed to comprise:
A p-type monocrystalline substrate;
A rectangle porous monocrystalline silicon trap, its trap body embed in the monocrystalline substrate, and its trap face and monocrystalline substrate surface maintain an equal level;
Two groups of thermocouple heaps, the silicon strip that mixes up type with difference is its thermocouple pairing material, all is in the upper area of rectangle porous monocrystalline silicon trap, arranges along the long side direction opposing parallel of trap respectively, its centre junction row occupy the centre of well region, and its edge junction row occupy the edge of well region;
A heating is first, is in the upper area of rectangle porous monocrystalline silicon trap, is arranged in along the longitudinal direction between the centre junction row of two groups of thermocouples heaps;
Article two, heat radiator covers the edge junction row of one group of thermocouple respectively, and expands to the monocrystalline substrate surface beyond the rectangle porous monocrystalline silicon well region;
A thermometric unit is in the silicon monocrystalline substrate surface, and near the heat radiator of one group of thermocouple heap;
Some interconnectors and press welding block are the thermocouple heap, and heating unit provides the passage that is connected with external circuit with thermometric unit; And
One deck passivation film covers all thermocouple heaps, heating unit, and heat radiator and thermometric unit separate itself and the fluid that flows through.
2. according to the described total silicon integrated flow sensors of claim 1, it is characterized in that described thermocouple heap mixes up monocrystalline silicon strip and p-type by the n-type and mixes up polysilicon strip and matched.
3. according to the described total silicon integrated flow sensors of claim 1, it is characterized in that described heating unit mixes up the formed resistor of monocrystalline silicon strip for the n-type.
4. according to the described total silicon integrated flow sensors of claim 1, it is characterized in that described heating unit mixes up the formed resistor of polysilicon strip for the p-type.
5. according to the described total silicon integrated flow sensors of claim 1, it is characterized in that described thermometric unit mixes up the formed resistor of polysilicon strip for the p-type.
6. according to the described total silicon integrated flow sensors of claim 1, it is characterized in that described passivation layer is the amorphous carborundum layer.
7. method of making integrated flow sensors as claimed in claim 1, its manufacturing step comprises:
Prepare a p-type monocrystalline substrate;
By thermal diffusion the monocrystalline silicon strip that two groups of n-types of formation mix up in the monocrystalline substrate is arranged;
In hydrofluoric acid solution, carry out anodic oxidation, in monocrystalline substrate, to form rectangle porous monocrystalline silicon trap, well region comprises that two groups of n-types that do not form porous monocrystalline silicon mix up the arrangement of monocrystalline silicon strip, the bottom and the side thereof of every monocrystalline silicon strip are all centered on by porous monocrystalline silicon, thereby itself and monocrystalline substrate are separated, also be separated out each other;
Silicon oxide layer deposited, and it is carried out lithography process, make it cover whole monocrystalline substrate surface, porous monocrystalline silicon trap surface, and every monocrystalline silicon strip all upper faces except that both ends;
Deposition p-type mixes up polysilicon layer, and it is carried out lithography process, make it form two groups of p-types at least and mix up the polysilicon strip arrangement, every p-type mixes up polysilicon strip and covers a n-type that is under it and mix up the monocrystalline silicon strip, and forms a p-type at the two ends that every p-type mixes up polysilicon strip respectively and mix up polysilicon and mix up the knot face that monocrystalline silicon directly contacts with the n-type;
Form a heating resistor bar, make it be arranged in two groups of p-types along the longitudinal direction and mix up between the polysilicon strip arrangement;
Form two heat radiator, the limit end that makes every heat radiator and one group of p-type mix up the polysilicon strip arrangement links to each other, and expands to the monocrystalline substrate district beyond the porous monocrystalline silicon well area;
Form a temperature detecting resistance bar, make it near a heat radiator that is in the monocrystalline substrate zone;
Form some interconnectors and press welding block by metallization, be the thermocouple heap, heating unit and thermometric unit provide the passage that is connected with external circuit; And
Deposit passivation layer makes it cover all thermocouple heaps, heating unit, heat radiator and thermometric unit.
8. according to the method for the described manufacturing integrated flow sensors of claim 7, it is characterized in that described heating unit mixes up the formed resistor of monocrystalline silicon strip for the n-type.
9. according to the method for the described manufacturing integrated flow sensors of claim 7, it is characterized in that described heating unit mixes up the formed resistor of polycrystalline bar for the p-type.
10. according to the method for the described manufacturing integrated flow sensors of claim 7, it is characterized in that described thermometric unit mixes up the formed resistor of polysilicon strip for the p-type.
11., it is characterized in that described passivation layer is the amorphous carborundum layer according to the method for the described manufacturing integrated flow sensors of claim 7.
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| DE602006019688D1 (en) * | 2006-03-31 | 2011-03-03 | Sensirion Holding Ag | Flow sensor with flow-adaptable analog-to-digital converter |
| DE602006019548D1 (en) * | 2006-03-31 | 2011-02-24 | Sensirion Holding Ag | Flow sensor with thermocouples |
| CN102620777A (en) * | 2012-03-29 | 2012-08-01 | 宝鸡恒通电子有限公司 | Diesel flow measuring sensor |
| MA40285A (en) * | 2014-06-02 | 2017-04-05 | Hat Teknoloji A S | Integrated, three-dimensional cell configuration, integrated cooling array and cell-based integrated circuit |
| CN112461312B (en) * | 2020-11-24 | 2022-08-30 | 中国科学院上海微***与信息技术研究所 | Thermal reactor type gas mass flow sensor and manufacturing method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5600174A (en) * | 1994-10-11 | 1997-02-04 | The Board Of Trustees Of The Leeland Stanford Junior University | Suspended single crystal silicon structures and method of making same |
| JPH09210748A (en) * | 1996-01-30 | 1997-08-15 | Matsushita Electric Works Ltd | Thermal type flow rate sensor |
| US5705745A (en) * | 1995-07-29 | 1998-01-06 | Robert Bosch Gmbh | Mass flow sensor |
| CN1174984A (en) * | 1996-08-23 | 1998-03-04 | 李韫言 | Thermal type flow sensor for very fine working |
| US6357294B1 (en) * | 1998-02-23 | 2002-03-19 | Hitachi, Ltd. | Thermal air flow sensor |
| US6684694B2 (en) * | 2000-12-28 | 2004-02-03 | Omron Corporation | Flow sensor, method of manufacturing the same and fuel cell system |
-
2004
- 2004-02-12 CN CNB2004100391393A patent/CN1297802C/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5600174A (en) * | 1994-10-11 | 1997-02-04 | The Board Of Trustees Of The Leeland Stanford Junior University | Suspended single crystal silicon structures and method of making same |
| US5705745A (en) * | 1995-07-29 | 1998-01-06 | Robert Bosch Gmbh | Mass flow sensor |
| JPH09210748A (en) * | 1996-01-30 | 1997-08-15 | Matsushita Electric Works Ltd | Thermal type flow rate sensor |
| CN1174984A (en) * | 1996-08-23 | 1998-03-04 | 李韫言 | Thermal type flow sensor for very fine working |
| US6357294B1 (en) * | 1998-02-23 | 2002-03-19 | Hitachi, Ltd. | Thermal air flow sensor |
| US6684694B2 (en) * | 2000-12-28 | 2004-02-03 | Omron Corporation | Flow sensor, method of manufacturing the same and fuel cell system |
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|---|---|
| CN1654927A (en) | 2005-08-17 |
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