CN102759551A - Perforated plate capacitor type gas sensor and preparation method - Google Patents
Perforated plate capacitor type gas sensor and preparation method Download PDFInfo
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- CN102759551A CN102759551A CN201210281916XA CN201210281916A CN102759551A CN 102759551 A CN102759551 A CN 102759551A CN 201210281916X A CN201210281916X A CN 201210281916XA CN 201210281916 A CN201210281916 A CN 201210281916A CN 102759551 A CN102759551 A CN 102759551A
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Abstract
The invention discloses a perforated plate capacitor type gas sensor which comprises a silicon substrate, a silicon top cover, an upper electrode film, a lower electrode film and an air-sensitive medium. The perforated plate capacitor type gas sensor is characterized in that (1) a micro pit is arranged on the silicon substrate, the lower electrode film is located at the bottom of the micro pit, the upper electrode film is adhered to the silicon top cover and suspended above the micro pit, and the electrode films are not contacted with each other to form a plate capacitor structure; (2) the air-sensitive medium is a chaotically interlaced micro nano wire or micro nano tube and located in the micro pit; and (3) a plurality of air holes are respectively arranged at the positions of the silicon substrate and the silicon top cover corresponding to the micro pit to form an airflow channel. The micro nano wire or micro nano tube serves as the air-sensitive film, superficial area is big, and air spreading and abortion are easy. Therefore, the perforated plate capacitor type gas sensor has the advantages of being rapid in response and high in sensitivity and can detect gas with extremely low concentration, and a preparation method is simple.
Description
Technical field
The present invention relates to the gas sensor technical field, be specifically related to a kind of capacity plate antenna formula gas sensor and preparation method thereof with perforation.
Background technology
Capacitance type gas sensor mainly is made up of the gentle sensitive media of electrode, and the air-sensitive medium causes that specific inductive capacity changes after adsorbing gas to be measured, thereby causes capacitance to change.The electrode of sensor mainly contains two kinds on capacity plate antenna type peace face interdigital electrode type, no matter is any, and the air-sensitive medium all must be in two electric fields that electrode produced (line of electric force must pass the air-sensitive medium).Otherwise the change of specific inductive capacity will be to not contribution of capacitance after the adsorbed gas.
Conventional plane interdigital capacitor sensor since be on the plane interdigital on deposition gas sensitive media film, line of electric force has half to pass substrate and do not obtain utilizing.For this reason, U.S. Seacoast company has reported a kind of overarm type interdigital electrode, and air-sensitive film is wrapped on each face up and down of overarm; So the line of electric force of the lower end of hanging oneself from a beam also is fully used; Thereby improved the sensitivity of sensor, referring to 1. Chemicapacitive microsensors for chemical warfare agent and toxic industrial chemical detection of document, Sensors and Actuators B; 2006,116:192 – 201; 2. Chemicapacitive microsensors for detection of explosives and TICs, SPIE, 2005,5986,59860M.The said firm has also developed the gas sensor of capacity plate antenna type, and two kinds of sensors are compared respectively has relative merits, and capacity plate antenna type highly sensitive be about 1.5 times of overarm type, but its response is too slow.Reason is that gas to be measured must get into through the electric pole plate of porous in the dielectric film of sensor, and the diffusion of gas needs the long time with abundant absorption, thereby the response time of this gas sensor is longer.
Except electrode structure, the microscopic appearance of air-sensitive medium also has very big influence to the performance of sensor.Existing air-sensitive medium, most films that all adopt densification cause the diffusion time of gas very long, make sensor can't realize quick response.If adopt loose porous air-sensitive film, not only help the diffusion absorption of gas, and increased the specific surface area of air-sensitive film greatly, adsorbable more gas to be measured, thus obtain higher sensitivity.
Though the air-sensitive medium of porous type can be prepared in easily the plane interdigital and the overarm interdigitation electrode on, as previously mentioned, the transducer sensitivity of this class formation is low.If can loose porous air-sensitive film be prepared between two electrode plate of plate condenser, not only can obtain high sensitivity, can also obtain simultaneously to respond fast.
Summary of the invention
Technical matters to be solved by this invention is: how in the gas sensor of capacity plate antenna type, introduce loose porous air-sensitive dielectric film, improving the sensitivity of sensor, and shorten the sensor's response time.
Technical matters proposed by the invention is to solve like this: the capacity plate antenna formula gas sensor that a kind of perforation is provided; Comprise silicon substrate, silicon top cover, upper electrode film, bottom electrode film, air-sensitive medium; It is characterized in that: silicon substrate is provided with little trap; The bottom electrode film is positioned at little trap bottom, and little trap has angled side walls with extraction electrode; The air-sensitive medium is positioned at little trap for chaotic micro-nano rice noodles or the micro-nano mitron that interweaves; Upper electrode film is attached on the silicon top cover and be suspended from the top of little trap, and silicon substrate and silicon top cover offer a plurality of pores respectively in the corresponding position of little trap.
According to the capacity plate antenna formula gas sensor of a kind of perforation provided by the present invention, said silicon substrate is the monocrystalline silicon of (100) tangential.
According to the capacity plate antenna formula gas sensor of a kind of perforation provided by the present invention, monocrystalline silicon or polysilicon that said silicon top cover is any tangential.
According to the capacity plate antenna formula gas sensor of a kind of perforation provided by the present invention, said upper and lower electrode film is any one in gold, copper, aluminium, nickel chromium triangle, platinum, titanium or the tungsten.
According to capacity plate antenna formula gas sensor of a kind of perforation provided by the present invention and preparation method thereof, said air-sensitive medium is any one polymkeric substance, inorganics or the organic-inorganic potpourri that can electricity spin.
The present invention also provides a kind of preparation method of capacity plate antenna formula gas sensor of perforation, it is characterized in that, may further comprise the steps:
A. silicon substrate is carried out the anisotropic wet corrosion, form little trap of bottom flat, sidewall slope;
B. adopt to be dry-etched in little trap and prepare pore;
C. utilize mask in little trap, to evaporate the bottom electrode film, and the sidewall extraction electrode of the little trap in edge;
D. adopt method of electrostatic spinning in little trap, to prepare the micro-nano rice noodles or the micro-nano mitron of air-sensitive medium;
E. adopt to be dry-etched on the silicon top cover and prepare pore;
F. the preparation upper electrode film is also graphical on the silicon top cover;
G. after upper/lower electrode is aimed at face-to-face, the silicon top cover is sticked on the silicon substrate.
The present invention compared with prior art has following advantage:
1. response is fast
Capacity plate antenna type gas sensor of the present invention all offer some pores on two electrode plate up and down; And the air-sensitive film between two battery lead plates is loose porous; Make air-flow to be measured to get into, and flow out, realize one-way gas flow from another pole plate from a pole plate.(unidirectional air-flow is provided by external micro air pump, and external air pump does not draw).And the capacity plate antenna type gas sensor of Seacoast company has only top crown that pore is arranged, and can not realize one-way gas flow, adds that its air-sensitive film is fine and close solid, and gas spreads very slow therein.Therefore, the response of the capacity plate antenna formula gas sensor with perforation of the present invention is faster.
2. highly sensitive
Air-sensitive dielectric film of the present invention is loose porous, and this not only helps shortening the response time, and has improved specific surface area greatly, thereby obtains higher sensitivity.Chinese patent ZL201010161765.5 discloses the open capacity plate antenna formula gas sensor of a kind of sidewall, through between upper and lower two battery lead plates, some pillars being set, and dielectric film is coated on the pillar, therefore also has bigger surface area.Obviously, the diameter of pillar is more little, and surface area is big more.But compare with the present invention, the size of pillar is difficult to accomplish that the nano wire that spins than electricity is thinner.Therefore, the surface area of air-sensitive film of the present invention is bigger, and the sensitivity of sensor is higher.
Description of drawings
Fig. 1 is the structural representation with capacity plate antenna formula gas sensor of perforation of the present invention, and wherein, Fig. 1 (a) is a side sectional view, and Fig. 1 (b) is the vertical view behind the removal top cover;
Fig. 2 is the preparation flow synoptic diagram with capacity plate antenna formula gas sensor of perforation of the present invention.
Wherein, 1 is silicon substrate, and 2 is the bottom electrode film, and 3 is the air-sensitive medium, and 4 is last conductive film, and 5 is the silicon top cover, and 6 is pore, and 7 are bottom electrode film lead-in wire, and 8 are the upper electrode film lead-in wire, and 9 is little trap, and 10 is bonding agent.
Embodiment
This capacity plate antenna formula gas sensor is as shown in Figure 1, comprises stacking silicon substrate and the silicon top cover that cements up and down, has dug a little trap on the silicon substrate; The air-sensitive medium confusion of micro-nano rice noodles or micro-nano tubulose interweaves in little trap; The bottom flat of little trap is provided with the bottom electrode film, and realizes drawing of electrode through little trap angled side walls; Upper electrode film faces little trap and attached on the silicon top cover; Silicon substrate and silicon top cover offer a plurality of pores respectively in the corresponding position of little trap, and extraneous air-flow vertically passes the pore on the silicon substrate, and the pore from the silicon top cover flows out.
It below is specific embodiment of the present invention.
Embodiment
As shown in Figure 1, a kind of perforate capacity plate antenna formula gas sensor, this structure comprises silicon substrate 1, aluminum bottom electrode film 2, the air-sensitive medium 3 of nano wire film type, aluminum upper electrode film 4, the silicon top cover 5 of insulation.Preparation flow is following: the first step; Select for use 300
monocrystalline silicon of thick, (100) tangential is as the silicon substrate 1 of insulation; Adopt KOH to erode away square etch pit as corrosive liquid; Etch pit opening 3mm * 3mm; The length of side is along [110] crystal orientation family direction; About 3
of the degree of depth, obtain bottom flat, 4 sidewalls and all be little trap 9 of 54.7 °.Second step; Adopt dry etching to begin etching pore 6 from the back side of silicon substrate 1; About 50
of pore 6 diameters; About 100
in interval; The position of etching is over against little trap 9, and the whole silicon wafer etching is worn.(pore does not draw by actual ratio in Fig. 1, Fig. 2).The 3rd step; Adopt evaporation method in little trap depositing metal aluminium as the bottom electrode film; Utilize mask to cover during evaporation, only make bottom deposit aluminium film at little trap, and be laid with a bottom electrode film lead-in wire 7 and arrive the upper surface of silicon substrate 1 outside little trap 9 along a sidewall; About 600 nm of aluminium film thickness, the nickel chromium triangle prime coat of its 150nm that has an appointment down.The 4th step, the method for employing electrostatic spinning, the air-sensitive medium 3 of coating one deck nanometer wire on bottom electrode.In the present embodiment, the material of spinning adopts polymer poly epichlorokydrin (PECH).Through regulating electrostatic spinning process, obtain the nano wire of diameter about 680-930nm.When electricity spins,, make the PECH nano wire of preparation be positioned among little trap 9 through adopting bushing.The 5th step; Adopt the thick silicon chip of another piece 300
as silicon top cover 5, adopt with second go on foot identical technology etch therein about 50
of several diameterspore 6.In the 6th step,, utilize mask to obtain upper electrode film pattern and the upper electrode film lead-in wire 8 of 2.8mm * 2.8mm at silicon top cover 5 evaporation Ni-Cr/Al upper electrode films 4.Evaporation has the position of electrode film to be covered with pore 6.The 7th step, silicon top cover 5 back-offs are come, make that upper electrode film 4 on it is aimed at the bottom electrode film 2 on the silicon substrate 1 face-to-face after, utilize resin 10 that silicon top cover 5 is sticked on the silicon substrate 1.During stickup, around little trap 9, evenly apply one deck resin, to avoid bonding plane gas leakage as far as possible.Before the stickup, silicon substrate 1 and silicon top cover 5 are all carried out suitable cutting, made the solder joint of pasting back upper electrode film lead-in wire 8 and bottom electrode film lead-in wire 7 all not be covered.
The final capacitance type sensor advantages of small volume that obtains of present embodiment, general size is 10 * 10 * 0.6mm3, and it vertically is installed in the gas piping, the external micro air pump of gas piping makes gas to be measured vertically pass capacitor plate.Therefore, the response of this capacitance type gas sensor is very fast, and response time of chloroethyl ethyl thioether (CEES) gas of 50mg/m3 is merely 12s, and minimum detection limit is about 0.35mg/m3, shows very high sensitivity.
Claims (7)
1. the capacity plate antenna formula gas sensor of a perforation; Comprise silicon substrate, silicon top cover, upper electrode film, bottom electrode film, air-sensitive medium; It is characterized in that: silicon substrate is provided with little trap, and the bottom electrode film is positioned at little trap bottom, and little trap has angled side walls with extraction electrode; The air-sensitive medium is micro-nano rice noodles or micro-nano mitron, is positioned at little trap; Upper electrode film is attached on the silicon top cover and be suspended from the top of little trap, and silicon substrate and silicon top cover offer a plurality of pores respectively in the corresponding position of little trap.
2. the capacity plate antenna formula gas sensor of a kind of perforation according to claim 1 is characterized in that: said silicon substrate is the monocrystalline silicon of (100) tangential.
3. the capacity plate antenna formula gas sensor of a kind of perforation according to claim 1 is characterized in that: monocrystalline silicon or polysilicon that said silicon top cover is any tangential.
4. the capacity plate antenna formula gas sensor of a kind of perforation according to claim 1 is characterized in that: said upper and lower electrode film is in gold, copper, aluminium, nickel chromium triangle, platinum, titanium or the tungsten any one.
5. the preparation method of the capacity plate antenna formula gas sensor of a kind of perforation according to claim 1 is characterized in that: said air-sensitive medium is any one polymkeric substance, inorganics or the organic-inorganic potpourri that can electricity spin.
6. the preparation method of the capacity plate antenna formula gas sensor of a perforation is characterized in that, may further comprise the steps:
A, silicon substrate is carried out anisotropic wet corrosion, form little trap of bottom flat, sidewall slope;
B, employing are dry-etched in little trap and prepare pore;
C, utilize mask in little trap, to evaporate the bottom electrode film, and along the sidewall extraction electrode of little trap;
D, employing method of electrostatic spinning prepare the micro-nano rice noodles or the micro-nano mitron of air-sensitive medium in little trap;
E, employing are dry-etched on the silicon top cover and prepare pore;
F, on the silicon top cover preparation upper electrode film and graphical;
G, upper/lower electrode stick on the silicon top cover on the silicon substrate after aiming at face-to-face.
7. the preparation method of the capacity plate antenna formula gas sensor of a kind of perforation according to claim 6 is characterized in that: said air-sensitive medium is any one polymkeric substance, inorganics or the organic-inorganic potpourri that can electricity spin.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103713022A (en) * | 2013-12-07 | 2014-04-09 | 太原理工大学 | Preparation method for polydimethylsiloxane micro-thin film capacitive biosensor |
| CN105081749A (en) * | 2015-08-10 | 2015-11-25 | 成都亨通兆业精密机械有限公司 | External perforating method for sensor |
| CN108120904A (en) * | 2016-11-30 | 2018-06-05 | 全球能源互联网研究院 | A kind of SF6 gas sensors and preparation method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101281154A (en) * | 2008-05-21 | 2008-10-08 | 中国科学院合肥物质科学研究院 | Capacitance type gas sensor based on carbon nano-tube array and preparing method thereof |
| KR20090055276A (en) * | 2007-11-28 | 2009-06-02 | (주)와이즈산전 | Gas sensor using capacitance |
| CN101825511A (en) * | 2010-05-04 | 2010-09-08 | 电子科技大学 | Minitype capacitance type gas sensor and preparation method thereof |
| CN102590280A (en) * | 2012-03-02 | 2012-07-18 | 电子科技大学 | Gas sensor array based on microwell structure and manufacturing method of gas sensor array |
-
2012
- 2012-08-09 CN CN201210281916XA patent/CN102759551A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20090055276A (en) * | 2007-11-28 | 2009-06-02 | (주)와이즈산전 | Gas sensor using capacitance |
| CN101281154A (en) * | 2008-05-21 | 2008-10-08 | 中国科学院合肥物质科学研究院 | Capacitance type gas sensor based on carbon nano-tube array and preparing method thereof |
| CN101825511A (en) * | 2010-05-04 | 2010-09-08 | 电子科技大学 | Minitype capacitance type gas sensor and preparation method thereof |
| CN102590280A (en) * | 2012-03-02 | 2012-07-18 | 电子科技大学 | Gas sensor array based on microwell structure and manufacturing method of gas sensor array |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103713022A (en) * | 2013-12-07 | 2014-04-09 | 太原理工大学 | Preparation method for polydimethylsiloxane micro-thin film capacitive biosensor |
| CN103713022B (en) * | 2013-12-07 | 2015-12-09 | 太原理工大学 | Polydimethylsiloxanemicro-thin micro-thin film capacitive biosensor preparation method |
| CN105081749A (en) * | 2015-08-10 | 2015-11-25 | 成都亨通兆业精密机械有限公司 | External perforating method for sensor |
| CN108120904A (en) * | 2016-11-30 | 2018-06-05 | 全球能源互联网研究院 | A kind of SF6 gas sensors and preparation method thereof |
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Application publication date: 20121031 |