CN218646885U - Novel penetration type multi-channel gas sensor of MEMS (micro-electromechanical systems) process - Google Patents
Novel penetration type multi-channel gas sensor of MEMS (micro-electromechanical systems) process Download PDFInfo
- Publication number
- CN218646885U CN218646885U CN202023271071.5U CN202023271071U CN218646885U CN 218646885 U CN218646885 U CN 218646885U CN 202023271071 U CN202023271071 U CN 202023271071U CN 218646885 U CN218646885 U CN 218646885U
- Authority
- CN
- China
- Prior art keywords
- film
- gas
- layer
- sensitive
- gas sensor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
Abstract
A novel penetration type multi-channel gas sensor of an MEMS (micro-electromechanical system) process solves the problem that the response time and the recovery time of a gas sensor to low-concentration gas are long due to the fact that gas flow can only pass through the upper surface of a packaging shell of a gas sensor array chip and gas molecules reach the surface of a gas sensitive material of the gas sensor and mainly transfer mass through gas diffusion, and comprises a Si substrate, a lower surface corrosion window, a through hole and a gas sensitive film, wherein the upper surfaces of the Si substrate and the through hole are provided with a second surfaceA layer of Si 3 O 4 Film, first layer Si 3 O 4 The surface of the film is provided with Pt film heating wires and a first layer of Si 3 O 4 The surfaces of the film and the Pt film heating wire are provided with second layers of Si 3 O 4 The surface of Au film gas-sensitive electrode is equipped with gas-sensitive film, which is composed of first layer of Si 3 O 4 Film, pt film heater wire, second layer Si 3 O 4 The multilayer composite film formed by the film, the Au film gas-sensitive electrode and the gas-sensitive film is penetrated by the upper surface corrosion window so as to have a bridge structure.
Description
Technical Field
The utility model relates to a gas sensor specifically is a novel penetrating type multichannel gas sensor of MEMS technology.
Background
The micro-hotplate type gas sensor is a suspended film structure manufactured on a silicon substrate, and the suspended film consists of an upper dielectric layer, a lower dielectric layer, a heating wire in the middle, a gas-sensitive electrode above the gas-sensitive film and the gas-sensitive film. The suspended film structure of the micro-hotplate type gas sensor is mainly divided into three typical structures, namely a bridge structure with a surface sacrificial layer corroded, a bridge structure with a front surface bulk silicon corroded and a diaphragm structure with a back surface bulk silicon corroded, and gas flow cannot penetrate through a gas sensor silicon substrate with the three structures. A plurality of micro-hotplate type gas sensors are manufactured on a micro-hotplate (MHP) on the same chip by utilizing a silicon-based micro-machining technology and are packaged in a packaging shell with air holes on the upper surface to manufacture a gas sensor array chip, and the gas sensor array chip has the advantages of small size, low power consumption, low cost, easiness in integration and the like. When the gas sensor array chip is used, when gas components or gas concentrations in airflow around a package housing of the gas sensor array chip are changed, for example, the concentration of gas a in the airflow is different from the concentration of gas a on the surface of a gas-sensitive film of the gas sensor, gas molecules a on the surface of the gas-sensitive film of the gas sensor and gas molecules a in the airflow are diffused due to the concentration difference, mass transfer occurs, the number of gas molecules a adsorbed on the surface of the gas-sensitive film of the gas sensor is changed, and thus a gas-sensitive signal is changed. Now, since the gas flow can only pass through the upper surface of the package housing of the gas sensor array chip, the response and recovery time of the gas sensor array chip can be affected. According to the basic law of molecular diffusion, the value of the diffusion flux of gas molecules is proportional to the difference in gas concentration, and therefore, as the difference between the concentration of a gas in the gas stream and the concentration of a gas at the surface of the gas-sensitive film of the gas sensor is smaller, the smaller the gas diffusion flux, resulting in longer response time and recovery time of the gas sensor for low-concentration gases.
SUMMERY OF THE UTILITY MODEL
To the above-mentioned condition, for overcoming prior art's defect, the utility model provides a novel penetrating multichannel gas sensor of MEMS technology, the effectual solution now because the air current can only follow the upper surface process of gas sensor array chip's encapsulation shell, gas molecule reachs gas sensor's gas sensitive material surface and mainly passes through the gas diffusion mass transfer, leads to the long problem of response time and recovery time of gas sensor to the low concentration.
In order to achieve the above object, the utility model provides a following technical scheme: the utility model discloses a Si substrate, first layer Si3N4 film, pt film heater strip, second floor Si3N4 film, au film gas sensitive electrode, upper surface corrosion window, lower surface corrosion window, through-hole and gas sensitive film, the upper surface of Si substrate and through-hole all is provided with first layer Si substrate 3 O 4 Film, first layer Si 3 O 4 The surface of the film is provided with Pt film heating wires, and the first layer of Si 3 O 4 The surfaces of the film and the Pt film heating wire are provided with second layers of Si 3 O 4 Film, second layer of Si 3 O 4 An Au film gas-sensitive electrode is arranged on the surface of the film, a gas-sensitive film is arranged on the surface of the Au film gas-sensitive electrode, and the gas-sensitive electrode is composed of a first layer of Si3N4 film, a Pt film heating wire and a second layer of Si 3 O 4 The multilayer composite film formed by the film, the Au film gas-sensitive electrode and the gas-sensitive film is penetrated by the upper surface corrosion window so as to have a bridge structure,a first layer of Si disposed on the lower surface of the Si substrate 3 O 4 Film and second layer of Si 3 O 4 The film is penetrated by the lower surface corrosion window to form a hole structure, the upper surface corrosion window, the lower surface corrosion window and the through hole are connected to form a penetration channel, and a plurality of structures are simultaneously manufactured on the Si substrate to form the penetration type multi-channel gas sensor.
Has the beneficial effects that: the utility model discloses a penetration multichannel gas sensor who prepares adopts front and back corrosion to combine to form penetration gas channel, makes the air current can pass perpendicularly the utility model discloses a penetration multichannel gas sensor, gas molecule flow flux is directly proportional to the product of gas concentration and air current speed, consequently than the gas sensor who relies on gas diffusion mass transfer in the past mainly, has bigger gas molecule flow flux, when low concentration gas detection, is favorable to obtaining faster gas response speed and recovery speed; the adoption of the penetrating type multi-channel gas sensor is matched with a corresponding packaging structure with an air flow penetrating effect, the purposes of improving the gas response speed and the recovery speed of the sensor can be achieved, the sensor chip can be in quick and effective contact with the air flow formed by the introduced test gas, the response effect is improved, and meanwhile, the device has the characteristics of low cost, small size, low power consumption and the like.
Drawings
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a schematic cross-sectional view of a transmission-type multi-channel gas sensor according to the present invention;
FIG. 2 is a schematic plan view of the upper surface of the transmission multi-channel gas sensor of the present invention;
FIG. 3 is a schematic plan view of the lower surface of the transmission multi-channel gas sensor of the present invention;
FIG. 4 is a schematic cross-sectional view of a transmission-type multi-channel gas sensor of the present invention in a transmission-type package housing;
fig. 5 to 11 are schematic sectional views showing the effects achieved in steps (2) to (8) according to the corresponding embodiments of the present invention;
reference numbers in the figures: 1. a Si substrate; 2. first layer of Si 3 O 4 A film; 3. a Pt film heating wire; 4. second layer of Si 3 O 4 A film; 5. an Au thin film gas-sensitive electrode; 6. an upper surface erosion window; 7. a lower surface erosion window; 8. a through hole; 9. a gas-sensitive film; 10. a multi-channel transmissive gas sensor chip; 11. a pad of the package housing; 12. a cover; 13. a base; 14. a through hole on the base.
Detailed Description
The following describes the present invention in further detail with reference to fig. 1-11.
Embodiments are given by fig. 1 to 11, and the utility model provides a novel penetration type multi-channel gas sensor of MEMS technology, including Si substrate 1, first layer Si3N4 film 2, pt film heater strip 3, second layer Si 3 O 4 The gas sensor comprises a film 4, an Au film gas-sensitive electrode 5, an upper surface corrosion window 6, a lower surface corrosion window 7, a through hole 8 and a gas-sensitive film 9, wherein the upper surfaces of a Si substrate 1 and the through hole 8 are respectively provided with a first layer of Si 3 O 4 Film 2, first layer Si 3 O 4 The surface of the film 2 is provided with a Pt film heating wire 3, and the first layer of Si 3 O 4 The surfaces of the film 2 and the Pt film heating wire 3 are both provided with a second layer of Si3N4 film 4, and the second layer of Si 3 O 4 The surface of the film 4 is provided with an Au film gas-sensitive electrode 5, the surface of the Au film gas-sensitive electrode 5 is provided with a gas-sensitive film 9, and the first layer of Si is formed 3 O 4 A multilayer composite film consisting of a film 2, a Pt film heater strip 3, a second layer Si3N4 film 4, an Au film gas-sensitive electrode 5 and a gas-sensitive film 9 is penetrated by an upper surface corrosion window 6 to form a bridge structure, and a first layer Si arranged on the lower surface of the Si substrate 1 3 O 4 Film 2 and second layer Si 3 O 4 The film 4 is penetrated by the lower surface etching window 7 to have a hole structure, the upper surface etching window 6, the lower surface etching window 7 and the through hole 8 are connected to form a penetration channel, and a plurality of the above structures are simultaneously manufactured on the Si substrate 1 to form a penetration multichannelA gas sensor.
The MEMS process of the novel penetration type multi-channel gas sensor of the MEMS process comprises the following steps:
1) Selecting materials: selecting a single-side polished silicon wafer with the thickness of 500 microns, the diameter of 100 millimeters and the (100) crystal orientation for later use;
2) Manufacturing a first Si3N4 film 2: depositing Si3N4 films on the upper and lower surfaces of the silicon substrate 1 of the silicon wafer in the step (1), and completing the process by chemical vapor deposition such as LPCVD or PECVD to obtain low-stress Si with the thickness of 300 nanometers 3 O 4 A film;
3) Manufacturing a Pt thin film heating wire 3: manufacturing a Pt heating wire on the upper surface of the silicon wafer after the step (2), coating photoresist and photoetching to ensure that the silicon wafer only exposes the position needing sputtering of the heating wire, and the other parts are well protected by the photoresist; sputtering a chromium metal transition layer and a Pt film, wherein the thickness is 100 nanometers; soaking the silicon wafer in a photoresist corrosive liquid, finishing the graphical processing of the Pt film in a stripping mode, and cleaning the silicon wafer by using alcohol and deionized water;
4) Manufacturing a second Si3N4 film 4: depositing Si on the upper and lower surfaces of the silicon wafer after the step (3) 3 O 4 A film is formed by chemical vapor deposition such as LPCVD or PECVD, and Si 3 O 4 The thickness of the film is 300 nanometers; the completion scheme is shown in FIG. 7;
5) Manufacturing an Au thin film gas-sensitive electrode 5: manufacturing an Au thin film gas-sensitive electrode on the upper surface of the silicon wafer after the step (4), coating photoresist and photoetching to ensure that the silicon wafer is only exposed at the position where the gas-sensitive electrode needs to be deposited, and the other parts are well protected by the photoresist; sputtering a chromium metal transition layer and an Au film with the thickness of 100 nanometers; soaking the silicon wafer in a photoresist corrosive liquid, finishing the graphical processing of the Au thin film in a stripping mode, and cleaning the silicon wafer by using alcohol and deionized water;
6) Manufacturing an upper surface corrosion window 6 and a lower surface corrosion window 7: respectively photoetching the upper surface of the silicon wafer after the step (5), defining an upper surface etching window 6, and etching Si by adopting a dry etching process 3 O 4 Film until the silicon substrate and the metal heating wire are exposedThe bonding pad of (a); photoetching the lower surface of the silicon wafer, defining a lower surface etching window 7, and etching Si by dry etching process 3 O 4 A film is formed until the silicon substrate 1 is exposed;
7) Etching the silicon substrate to form the through hole 8: soaking the silicon wafer after the step (6) in 20% TMAH solution to obtain (CH) 3 ) 4 The NOH solution is selected to be in water bath at 85 ℃ and is etched for 4-6 hours, so that the silicon substrate penetrates through to form a through hole 8, and the first layer of Si is arranged on the through hole 8 3 O 4 Film 2, pt film heater strip 3, second layer Si 3 O 4 The multilayer composite film consisting of the film 4 and the Au film gas-sensitive electrode 5 is completely suspended;
8) Manufacturing a gas-sensitive film 9: finishing the processing of the gas-sensitive film above the suspended multilayer composite film of the silicon chip after the step (7) by adopting a gas-sensitive ink printing mode to finish the processing of the multi-channel penetrating gas sensor;
9) Slicing and packaging: cutting the silicon wafer after the step (8) into a multi-channel penetrating gas sensor chip 10 by adopting a laser cutting process; coating silver paste at a non-through hole on the bottom surface of the chip, aligning a through hole of the chip with a through hole of the packaging shell, adhering the through hole to the base 13, starting from 25 ℃ at room temperature by using a muffle furnace, heating the through hole to 150 ℃ after 30 minutes, keeping the temperature for one hour at 150 ℃, and then naturally cooling to finish annealing and curing of the silver paste; connecting a bonding pad of the chip with a bonding pad of the packaging base by using a gold wire ball bonding machine; the lid 12 of the package is adhesively secured over the base 13.
Has the advantages that: the utility model discloses a penetration multichannel gas sensor who prepares adopts front and back corrosion to combine to form penetration gas channel, makes the air current can pass perpendicularly the utility model discloses a penetration multichannel gas sensor, gas molecule flow flux is directly proportional to the product of gas concentration and air current speed, consequently than the gas sensor who relies on gas diffusion mass transfer in the past mainly, has bigger gas molecule flow flux, when low concentration gas detection, is favorable to obtaining faster gas response speed and recovery speed; the adoption of the penetrating type multi-channel gas sensor is matched with a corresponding packaging structure with an air flow penetrating effect, the purposes of improving the gas response speed and the recovery speed of the sensor can be achieved, the sensor chip can be in quick and effective contact with the air flow formed by the introduced test gas, the response effect is improved, and meanwhile, the device has the characteristics of low cost, small size, low power consumption and the like.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (1)
1. A novel penetration type multi-channel gas sensor of MEMS process comprises a Si substrate (1) and a first layer of Si 3 O 4 A film (2), a Pt film heating wire (3) and a second layer Si 3 O 4 Film (4), au film gas-sensitive electrode (5), upper surface corrosion window (6), lower surface corrosion window (7), through-hole (8) and gas-sensitive film (9), its characterized in that: the upper surfaces of the Si substrate (1) and the through hole (8) are provided with a first layer of Si 3 O 4 Film (2), first layer Si 3 O 4 The surface of the film (2) is provided with Pt film heating wires (3), and the first layer of Si 3 O 4 The surfaces of the film (2) and the Pt film heating wire (3) are both provided with a second layer of Si 3 O 4 Film (4), second layer Si 3 O 4 The surface of the film (4) is provided with an Au film gas-sensitive electrode (5), the surface of the Au film gas-sensitive electrode (5) is provided with a gas-sensitive film (9), and the gas-sensitive film is composed of a first layer of Si 3 O 4 A film (2), a Pt film heating wire (3) and a second layer Si 3 O 4 A multilayer composite film consisting of the film (4), the Au film gas-sensitive electrode (5) and the gas-sensitive film (9) is penetrated by an upper surface corrosion window (6) to form a bridge structure, and a first layer of Si is arranged on the lower surface of the Si substrate (1) 3 O 4 Film(s)(2) And a second layer of Si 3 O 4 The film (4) is penetrated by the lower surface corrosion window (7) so as to have a hole structure, the upper surface corrosion window (6), the lower surface corrosion window (7) and the through hole (8) are connected to form a penetration channel, and a plurality of structures are simultaneously manufactured on the Si substrate (1) so as to form the penetration type multi-channel gas sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202023271071.5U CN218646885U (en) | 2020-12-30 | 2020-12-30 | Novel penetration type multi-channel gas sensor of MEMS (micro-electromechanical systems) process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202023271071.5U CN218646885U (en) | 2020-12-30 | 2020-12-30 | Novel penetration type multi-channel gas sensor of MEMS (micro-electromechanical systems) process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218646885U true CN218646885U (en) | 2023-03-17 |
Family
ID=85489024
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202023271071.5U Active CN218646885U (en) | 2020-12-30 | 2020-12-30 | Novel penetration type multi-channel gas sensor of MEMS (micro-electromechanical systems) process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN218646885U (en) |
-
2020
- 2020-12-30 CN CN202023271071.5U patent/CN218646885U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7603898B2 (en) | MEMS structure for flow sensor | |
| KR100812996B1 (en) | Micro gas sensor and method for manufacturing the same | |
| KR100479687B1 (en) | Cantilever sensor and method for fabrication thereof | |
| KR960015067B1 (en) | Silicon-based mass airflow sensor | |
| US20090151429A1 (en) | Micro gas sensor and manufacturing method thereof | |
| EP0798554A2 (en) | Sensor and method of fabrication | |
| JP3379736B2 (en) | Heat propagation time measurement type flow sensor and its manufacturing method | |
| JP2005505758A (en) | Micromachining type thermal conductivity sensor with porous cover | |
| CN101344413A (en) | Flat diaphragm type gas flow sensor and method of producing the same | |
| CN112730520A (en) | Penetration type multi-channel gas sensor of MEMS (micro-electromechanical systems) process | |
| JP3324855B2 (en) | Mass flow sensor | |
| CN106093138B (en) | Pass through the manufacturing method and sensor of the sensor of metal oxide detection gas | |
| CN218646885U (en) | Novel penetration type multi-channel gas sensor of MEMS (micro-electromechanical systems) process | |
| KR20090124011A (en) | Packaging substrate and gas sensing device having the same, and method for manufacturing the same | |
| JPH04269628A (en) | Sensor for measuring speed and flow rate of fluid medium and manufacture thereof | |
| CN201247082Y (en) | Flat diaphragm type gas flow sensor | |
| CN111397776B (en) | Temperature and pressure composite sensor | |
| US6265750B1 (en) | Electrochemical gas sensor and method of making the same | |
| CN115541099A (en) | Capacitive microfluidic pressure sensor, preparation method and microfluidic chip thereof | |
| KR20050063097A (en) | Micro electro mechanical system sensor capable of simultaneously sensing pressure, temperature and acceleration, fabrication method therefor, and tire pressure monitoring system using the same | |
| JP2621928B2 (en) | Gas detector | |
| JP3897296B2 (en) | Microsensor and manufacturing method thereof | |
| JP4265351B2 (en) | Sensor device having a membrane | |
| KR100679894B1 (en) | Gas sensor and method for fabricating the same | |
| JP5949573B2 (en) | Manufacturing method of physical quantity sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |