CN115266848A - Multi-channel gas sensor and preparation method thereof - Google Patents
Multi-channel gas sensor and preparation method thereof Download PDFInfo
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- CN115266848A CN115266848A CN202211017490.7A CN202211017490A CN115266848A CN 115266848 A CN115266848 A CN 115266848A CN 202211017490 A CN202211017490 A CN 202211017490A CN 115266848 A CN115266848 A CN 115266848A
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- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/14—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature
Abstract
The invention relates to the field of gas sensors, and discloses a multi-channel gas sensor and a preparation method thereof, wherein the multi-channel gas sensor comprises a substrate, a substrate layer, a heating resistor layer, an isolation medium layer and an interdigital electrode layer; the substrate layer is arranged on the substrate; the heating resistor layer is arranged on the substrate layer; the heating resistor layer comprises a first number of heating resistor arrays; the resistance values of the heating resistor arrays are different; the isolation medium layer is arranged on the heating resistor layer; the interdigital electrode layer is arranged on the isolation medium layer; the interdigital electrode layer comprises a first number of interdigital electrode arrays; the interdigital electrode arrays correspond to the heating resistor arrays one by one and cover the heating resistor arrays. Thus, the obtained multi-channel gas sensor has the advantages of integration and miniaturization.
Description
Technical Field
The invention relates to the field of gas sensors, in particular to a multi-channel gas sensor and a preparation method thereof.
Background
The gas sensor has wide application in the fields of industrial production, family safety, environmental monitoring, military anti-terrorism, aerospace and the like, and the research and development of the gas sensor are more and more important along with the higher requirements of the fields on the precision, the performance and the stability of the gas sensor.
In practical applications, for example, in an electronic nose system, the gas to be detected often has complex components and different concentrations, and the gas sensitive material with a single component usually only responds to one or more gases, so that it is difficult to have a comprehensive analysis result on the gas to be detected, and thus, multiple gas sensors are required to perform cross analysis, so that the gas sensor array has a complex structure, and is difficult to integrate and miniaturize.
Disclosure of Invention
The invention aims to solve the technical problem that a gas sensor array is difficult to integrate and miniaturize.
In order to solve the technical problem, the application discloses a multi-channel gas sensor on one hand, which comprises a substrate, a substrate layer, a heating resistor layer, an isolation medium layer and an interdigital electrode layer;
the substrate layer is arranged on the substrate;
the heating resistor layer is arranged on the substrate layer; the heating resistor layer comprises a first number of heating resistor arrays; the resistance values of the heating resistor arrays are different;
the isolation medium layer is arranged on the heating resistor layer;
the interdigital electrode layer is arranged on the isolation medium layer; the interdigital electrode layer comprises a first number of interdigital electrode arrays; the interdigital electrode arrays correspond to the heating resistor arrays one by one and cover the heating resistor arrays.
Further, the substrate layers include a first substrate layer and a second substrate layer; the first substrate layer is arranged on the base; the second substrate layer is arranged on the first substrate layer;
the first substrate layer is used for insulation;
the second substrate layer is used for insulating and resisting cold and hot shock caused by rapid temperature rise of the heating resistor layer.
Further, the heating resistor layer further comprises a first number of marks;
the marks correspond to the heating resistor arrays one by one.
Further, each heating resistor array comprises a second number of heating resistors;
the resistance values of the heating resistors in each heating resistor array are the same;
the resistance values of the heating resistors are different between different heating resistor arrays.
Further, each interdigital electrode array comprises a second number of interdigital electrodes;
the interdigital electrodes correspond to the heating resistors one by one and cover the heating resistors.
Furthermore, the heating resistor and the interdigital electrode corresponding to the heating resistor form a suspension film, and a cavity is formed in a preset area outside the suspension film.
Furthermore, the heating resistor layer also comprises an electrode pad, and the electrode pad is connected with the heating resistor array through a routing;
and windowing the position of the isolation dielectric layer corresponding to the electrode pad to expose the electrode pad.
The present application discloses in another aspect a method of making a multi-channel gas sensor, comprising the steps of:
providing a substrate;
forming a substrate layer on a substrate;
forming a heating resistor layer on the substrate layer; the heating resistor layer comprises a first number of heating resistor arrays; the resistance values of the heating resistor arrays are different;
depositing an isolation medium layer on the heating resistance layer;
forming an interdigital electrode layer on the isolation medium layer; the interdigital electrode layer comprises a first number of interdigital electrode arrays; the interdigital electrode arrays correspond to the heating resistor arrays one by one and cover the heating resistor arrays;
and removing the interdigital electrode array and the substrate with a preset depth at the preset area outside the interdigital electrode array by wet etching to obtain the multi-channel gas sensor.
Further, forming a substrate layer on the substrate, comprising:
forming a first substrate layer on a base by thermal oxidation;
a second substrate layer is formed on the first substrate layer.
Further, after depositing and forming an isolation medium layer on the heating resistor layer and before forming the interdigital electrode layer on the isolation medium layer, the method further comprises the following steps:
and etching and windowing the isolation medium layer to expose the electrode pad of the heating resistor layer.
Further, after forming the interdigital electrode layer on the isolation medium layer, removing the interdigital electrode array and a substrate with a preset depth at a preset area outside the interdigital electrode array by wet etching, and before obtaining the multi-channel gas sensor, the method further comprises:
and etching the preset area, and removing the substrate layer and the isolation medium layer in the preset area.
Adopt above-mentioned technical scheme, the multichannel gas sensor that this application provided has following beneficial effect:
the application discloses a multi-channel gas sensor which comprises a substrate, a substrate layer, a heating resistor layer, an isolation medium layer and an interdigital electrode layer; the substrate layer is arranged on the substrate; the heating resistance layer is arranged on the substrate layer; the heating resistor layer comprises a first number of heating resistor arrays; the resistance values of the heating resistor arrays are different; the isolation medium layer is arranged on the heating resistor layer; the interdigital electrode layer is arranged on the isolation medium layer; the interdigital electrode layer comprises a first number of interdigital electrode arrays; the interdigital electrode arrays correspond to the heating resistor arrays one by one and cover the heating resistor arrays. Thus, the obtained multi-channel gas sensor has the advantages of integration and miniaturization.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a schematic diagram of a multi-channel gas sensor according to an embodiment of the present disclosure;
FIG. 2 is a schematic diagram of a multi-channel gas sensor according to an embodiment of the present disclosure;
FIG. 3 is a schematic diagram of a multi-channel gas sensor according to an embodiment of the present disclosure;
FIG. 4 is a schematic diagram of a multi-channel gas sensor according to an embodiment of the present disclosure;
FIG. 5 is a schematic diagram of a multi-channel gas sensor according to an embodiment of the present disclosure;
FIG. 6 is a schematic flow chart illustrating a method for manufacturing a multi-channel gas sensor according to an embodiment of the present disclosure;
FIG. 7 is a schematic view of a manufacturing process of a multi-channel gas sensor according to an embodiment of the present disclosure;
FIG. 8 is a schematic diagram illustrating a manufacturing process of a method for manufacturing a multi-channel gas sensor according to an embodiment of the present disclosure;
FIG. 9 is a schematic diagram illustrating a manufacturing process of a method for manufacturing a multi-channel gas sensor according to an embodiment of the present disclosure;
FIG. 10 is a schematic diagram illustrating a manufacturing process of a method for manufacturing a multi-channel gas sensor according to an embodiment of the present disclosure;
FIG. 11 is a schematic diagram illustrating a manufacturing process of a method for manufacturing a multi-channel gas sensor according to an embodiment of the present disclosure;
fig. 12 is a schematic manufacturing flow chart of a method for manufacturing a multi-channel gas sensor according to an embodiment of the present disclosure.
The following is a supplementary description of the drawings:
1-a substrate layer; 11-a first substrate layer; 12-a second substrate layer; 100-a substrate; 2-a heating resistor layer; 20-heating an array of resistors; 21-identification; 200-heating resistance; 210-an electrode pad; 3-isolating the dielectric layer; 4-an interdigital electrode layer; 40-an array of interdigitated electrodes; 400-interdigital electrodes; 5-a suspended membrane; 6-cavity.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It should be apparent that the described embodiments are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic may be included in at least one implementation of the present application. In the description of the present application, it is to be understood that the terms "upper", "lower", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the application described herein may be implemented in sequences other than those illustrated or described herein.
Fig. 1 shows a schematic structural diagram of a multi-channel gas sensor provided by an embodiment of the present application, and as shown in fig. 1, the gas sensor includes a substrate 100, a substrate layer 1, a heating resistor layer 2, an isolation medium layer 3, and an interdigital electrode layer 4. The substrate layer is arranged on the substrate 100, the heating resistor layer 2 is arranged on the substrate layer 1, the isolation medium layer 3 is arranged on the heating resistor layer 2, and the interdigital electrode layer 4 is arranged on the isolation medium layer 3.
As an alternative implementation, fig. 2 shows a schematic structural diagram of a multi-channel gas sensor provided in an embodiment of the present application, specifically, fig. 2 is a cross-sectional view of the multi-channel gas sensor at a heating resistor array 20 in a heating resistor layer 2, as shown in fig. 2, a substrate layer 1 includes a first substrate layer 11 and a second substrate layer 12, where the first substrate layer 100 is disposed on a substrate 100, and the second substrate layer 12 is disposed on the first substrate layer 11. The first substrate layer 11 and the second substrate layer 12 can play an insulating role, so that the safe operation of the heating resistor layer 2 is ensured; the second substrate layer 12 can also resist cold and hot shock caused by rapid temperature rise of the heating resistor layer 2, so that the service life of the multi-channel gas sensor is prolonged, and the reliability of the multi-channel gas sensor is ensured. In addition, the arrangement of the first substrate layer 11 and the second substrate layer 12 can also counteract the internal stress generated by the first substrate layer and the second substrate layer in the film forming process, and avoid the warping after the film forming.
As an alternative embodiment, the material of the first substrate layer 11 is silicon dioxide, and the material of the second substrate layer 12 is silicon nitride. Silicon dioxide and silicon nitride are common materials in the MEMS manufacturing Process (micro fabrication Process), and can resist corrosion of silicon-based corrosive liquids such as TMAH.
As an alternative embodiment, the thickness of the first substrate layer 11 may be 2000A and the thickness of the second substrate layer may be 6000A.
As an alternative implementation, fig. 3 shows a schematic structural diagram of a multi-channel gas sensor provided in the embodiment of the present application, and as shown in fig. 2 and fig. 3, the heating resistor layer 2 may include a first number of heating resistor arrays 20. The resistance values of each heating resistor array 20 are different to meet the temperature requirements of different gas sensitive materials. Thus, one heating resistor array 20 corresponds to one gas sensor, and the heating resistor layer 2 can correspond to the gas sensors of the first quantity and the first kind, so that the multi-channel gas sensor can integrate a plurality of gas sensors, detect a plurality of kinds of gas simultaneously, and can meet the detection requirements of a detection system with complex gas components to be detected, such as an electronic nose system.
As an alternative embodiment, in the heating resistor layer 2, the heating resistor arrays 20 are mechanically independent from each other, and are independent from each other and do not affect each other in practical application. The number of the heating resistor arrays 20, i.e. the first number, may be determined according to the requirements of the actual detection system, and the specific value of the first number is not limited in this application.
As an alternative embodiment, each heating resistor array 20 includes a second number of heating resistors 200. The resistance values of the heating resistors 200 in each heating resistor array 20 are the same, so as to ensure that the temperatures in the heating resistor arrays 20 are consistent during power-on heating, and thus the internal heat of the corresponding gas sensor is uniform. The resistance values of the heating resistors 200 in different heating resistor arrays 20 are different, so that the resistance values of different heating resistor arrays 20 are different, and the requirements of different gas sensors on temperature are met.
As an alternative embodiment, the number of the heating resistors 200 in the heating resistor array 20, i.e. the second number, may be set according to the requirement of the actual detection system, and the specific value of the second number is not limited in this application.
As an alternative embodiment, the heating resistor 200 is a tantalum/platinum (Ta/Pt) resistor, in which tantalum is used as an electrode adhesion layer to ensure the adhesion of the heating resistor layer 2 to the bottom layer, i.e. the substrate layer 1, and ensure the structural integrity of the device; platinum has good electrothermal stability and chemical stability, and can heat the device to a target temperature with low power consumption, thereby ensuring the stable operation of the multi-channel gas sensor.
As an alternative embodiment, the width of the heating resistor 200 may be 12-15 μm, and the specific value may be different according to the setting of the resistance value.
In an alternative embodiment, the thickness of the tantalum material in the heating resistor 200 may be 300A, and the thickness of the platinum material may be 3000A.
As an alternative embodiment, the heating resistors 200 in each heating resistor array 20 are connected by a wire, and each heating resistor 200 is connected to one electrode pad 210. These electrode pads are arranged in positions near the edges in the entire heating resistor layer 2 for external connection. Specifically, the heating resistor 200 located inside the heating resistor layer 2 is routed to the outside of the heating resistor layer 2 via the corresponding electrode pad 210.
As an alternative embodiment, a common pad is disposed between each column of heating resistor arrays 20, and the common pad is connected to a corresponding column of heating resistor arrays 20.
As an alternative embodiment, the size of the electrode pad 210 and the common pad is 100 μm × 100 μm.
As an alternative embodiment, a first number of marks 21 are also provided on the heating resistor layer 2. The first number of marks 21 are respectively disposed beside the heating resistor arrays 20, so that the heating resistor arrays 200 correspond to each other one by one, and are used for distinguishing different heating resistor arrays 20.
As an alternative embodiment, the content of the identifier 21 may be a numerical value corresponding to the resistance value of the corresponding heating resistor array 20. For example, the multi-channel gas sensor is provided with 4 heating resistor arrays 20, the resistance values of the 4 heating resistor arrays 20 are respectively 30 Ω, 40 Ω, 50 Ω and 60 Ω, the corresponding marks 21 are respectively numbers "3", "4", "5" and "6", or numbers "30", "40", "50" and "60", the resistance values of the corresponding heating resistor arrays 20 are labeled and explained while different heating resistor arrays 20 are distinguished, and a user can conveniently select a suitable heating resistor array 20. The mark 21 may be any other mark capable of distinguishing different heating resistor arrays 20.
As an alternative embodiment, as shown in fig. 2, the isolation medium layer 3 completely covers the heating resistor layer 2, and the isolation medium layer 3 is windowed at the position corresponding to the electrode pad 210 and the common pad of the heating resistor layer 2, and exposes the electrode pad 210 and the common pad of the heating resistor layer 2.
As an alternative embodiment, the window of the isolation dielectric layer 3 should be slightly larger than the electrode pad 210 and the common pad of the heating resistor layer 2 in consideration of process error and the like. The size of the window is not specifically limited, and the size of the window can ensure that the electrode pad 210 and the common pad can be completely exposed, and can be adjusted according to actual process capability.
As an alternative embodiment, since the thickness of the insulating medium layer 3 is relatively thin, the pattern of the heating resistor layer 2 can still be seen through the insulating medium layer 3, and the position of the insulating medium layer 3 corresponding to the mark 21 on the heating resistor layer 2 does not need to be windowed.
As an optional implementation manner, the isolation medium layer 3 is made of silicon dioxide/silicon nitride, which, like the substrate layer 1, plays an insulating role, ensures safe operation of the heating resistor layer 2, counteracts internal stress generated by respective film formation, prolongs the service life of the multi-channel gas sensor, and ensures the reliability of the multi-channel gas sensor. Meanwhile, the materials of the isolation medium layer 3, the second substrate layer 12 and the first substrate layer 11 are arranged, so that the stress of the multi-channel gas sensor can be balanced, and warping caused by overlarge stress can be prevented.
As an alternative embodiment, the thickness of the silicon dioxide material in the isolation dielectric layer 3 may be 2000A, and the thickness of the silicon nitride material may be 4000A.
As an alternative implementation, fig. 4 shows a schematic structural diagram of a multi-channel gas sensor provided in the embodiment of the present application, and as shown in fig. 2 and fig. 4, the interdigital electrode layer 4 includes an interdigital electrode array 40 which may include a first number. The interdigital electrode array 40 corresponds to the heating resistor array 20 one by one, and the position of the interdigital electrode array 40 in the interdigital electrode layer 4 is consistent with the position of the heating resistor array 20 in the heating resistor layer 2, so that the interdigital electrode array 40 completely covers the heating resistor array 20, and the temperature environment provided by the heating resistor array 20 can cover the interdigital electrode array 40.
As an alternative embodiment, each interdigital electrode array 40 includes a second number of interdigital electrodes 400, and each interdigital electrode 400 is disposed at a position in the interdigital electrode layer 4 corresponding to the position in the heating resistor layer 2 of the corresponding heating resistor 200. The design of the interdigital electrodes 400 between different interdigital electrode arrays 40 is consistent, and optionally, the interdigital electrodes 400 between different interdigital electrode arrays 40 can be optimized according to actual requirements.
As an alternative embodiment, the width of the interdigital electrode 400 can be set to 7.5 μm.
As an alternative embodiment, the material of the interdigital electrode 400 is tantalum/platinum (Ta/Pt), wherein tantalum is used as an electrode adhesion layer to ensure the adhesion of the interdigital electrode layer 4 and the isolation medium layer 3 and ensure the structural integrity of the device; platinum, as an inert metal, can be used as an electrode material for testing the reaction of a gas sensitive material to a gas to be tested.
As an alternative embodiment, the thickness of the tantalum material in the interdigital electrode 400 can be 300A, and the thickness of the platinum material can be 3000A.
As an alternative implementation, the interdigital electrodes 400 in each interdigital electrode array 40 are connected by a wire, and each interdigital electrode 400 is connected to a pad, and these pads are arranged at a position where the whole interdigital electrode layer 4 can be close to the edge, so as to facilitate external connection. Specifically, the interdigital electrode 400 located on the inner layer of the interdigital electrode layer 4 leads the corresponding bonding pad to the outer side of the interdigital electrode layer 4 through routing.
As an alternative embodiment, a common pad is disposed between the interdigital electrode arrays 4, and the common pad connects all the interdigital electrode arrays 40.
As an alternative implementation, fig. 5 shows a schematic structural diagram of a multi-channel gas sensor provided in this embodiment, specifically, fig. 5 is a schematic structural diagram of a suspension film 5, as shown in fig. 5, the suspension film 5 is formed between a heating resistor 200 and an interdigital electrode 400 corresponding to the heating resistor, in a preset region outside the suspension film 5, both the isolation dielectric layer 3 and the substrate layer 1 are etched away, the suspension film 5 and the substrate 100 at the preset region are etched away by a preset depth, and a cavity 6 is formed between the suspension film 5 and a surrounding material.
As an alternative embodiment, the predetermined area is a rectangular area outside the suspension film, except for the heating resistor 200 and its circuit and the interdigital electrode 400 and its circuit, and the four corners of the rectangular area are designed with a rounded corner compensation structure to improve the mechanical strength of the suspension film 5.
As an alternative embodiment, the predetermined area may be a square area of 150 μm × 150 μm except for the heating resistor 200 and its lines and the interdigital electrode 400 and its lines.
As an alternative embodiment, different gas sensitive materials are coated on different suspension membranes 5 of the multi-channel gas sensor, so that different gases can be detected, and the multi-channel gas sensor can be applied to component analysis and environment detection in complex gas environments.
On the other hand, the present application further discloses a method for manufacturing a multi-channel gas sensor, and fig. 6 to 12 are schematic diagrams illustrating a manufacturing process of the method for manufacturing a multi-channel gas sensor provided in the embodiment of the present application, as shown in fig. 6 to 12, the method specifically includes the following steps:
s101: a substrate 100 is provided.
In the embodiment of the present application, the material of the substrate 100 is silicon.
S103: a substrate layer 1 is formed on a substrate 100.
In the present embodiment, the substrate layer 1 comprises a first substrate layer 11 and a second substrate layer 12. First, a layer of silicon dioxide is formed on the substrate 100 by thermal oxidation, resulting in the first substrate layer 11. After the first substrate layer 11 is formed, a layer of silicon nitride is deposited by Low Pressure Chemical Vapor Deposition (LPCVD) to form the second substrate layer 12.
S105: a heating resistor layer 2 is formed on a substrate layer 1.
In the embodiment of the present application, the heating resistor layer 2 includes a first number of heating resistor arrays 20, and the resistance value of each heating resistor array 2 is different. Each heating resistor array 20 includes a second number of heating resistors 200, the heating resistors 200 in each heating resistor array 2 have the same resistance, and the heating resistors 200 in different heating resistor arrays 2 have different resistances.
As an alternative embodiment, the heating resistor layer 2 may be made by a thermal evaporation or sputtering process, and the material of the heating resistor layer 2 is tantalum/platinum (Ta/Pt) metal.
S107: an isolating dielectric layer 3 is deposited on the heating resistor layer 2.
In the embodiment of the present application, silicon dioxide and silicon nitride are sequentially deposited by a Plasma Enhanced Chemical Vapor Deposition (PECVD) method to form the isolation dielectric layer 3.
As an optional implementation manner, after the isolation dielectric layer 3 is formed, a position, corresponding to the electrode pad 210 of the heating resistor layer 2, on the isolation dielectric layer 3 is etched away through a photolithography process, so as to form a window, and expose the electrode pad 210 of the heating resistor layer 2, thereby facilitating subsequent external connection.
S109: and forming an interdigital electrode layer 4 on the isolation medium layer 3.
In the embodiment of the present application, the interdigital electrode layer 4 includes a first number of interdigital electrode arrays 40, and the interdigital electrode arrays 40 correspond to the heating resistor arrays 20 one to one. Each interdigital electrode array 40 comprises a second number of interdigital electrodes 400, and the interdigital electrodes 400 correspond to the heating resistors 20 one by one, and cover the heating resistors 200.
As an alternative implementation manner, the interdigital electrode layer 4 can be made by using a thermal evaporation or sputtering process, and the material of the interdigital electrode layer 4 is tantalum/platinum (Ta/Pt) metal.
As an alternative implementation, a preset area outside the interdigital electrode 400 is etched, the substrate layer 1 and the isolation medium layer 3 in the preset area are removed, an etching window is formed, and the substrate 100 is removed by wet etching in the following step, so that the suspended film 5 is formed at the interdigital electrode 4.
As an alternative embodiment, the predetermined area is a rectangular area outside the suspension membrane 5 except for the heating resistor 200 and its circuit and the interdigital electrode 400 and its circuit, and the four corners of the rectangular area are designed with a rounded corner compensation structure to improve the mechanical strength of the suspension membrane 5. That is, the predetermined area is actually four trapezoidal areas with rounded corner compensation outside the floating membrane 5.
As an optional implementation manner, the substrate layer 1 and the isolation dielectric layer 3 in the preset region are etched through a photolithography process to expose the substrate 100 in the preset region, and an etching window is formed in the preset region, so that an etching solution can contact the substrate 100 through the etching window during subsequent wet etching.
S111: and removing the interdigital electrode array 40 and the substrate 100 with a preset depth at the preset area outside the interdigital electrode array 40 by wet etching to obtain the multi-channel gas sensor.
In the embodiment of the application, the interdigital electrode array 40 and a substrate 100 with a predetermined depth at a predetermined region outside the interdigital electrode array 40 are removed by a tetramethylammonium hydroxide (TMAH) wet etching, a suspension film 5 is formed at each interdigital electrode 400 of the interdigital electrode array 40, and a cavity 6 is formed between the suspension film 5 and a surrounding material, so as to obtain the multi-channel gas sensor.
As an alternative embodiment, in the wet etching, the etching solution contacts the substrate 100 through the etching window formed at the predetermined region, and etches the substrate 100 in all directions, thereby etching not only the suspended film 5 and the substrate 100 under the predetermined region, but also the substrate 100 in a region outside the predetermined region.
As an alternative embodiment, the time or the etching depth of the wet etching may be adjusted according to actual requirements, and any time or etching depth that can completely etch the substrate 100 under the suspended film 5 and the predetermined region without completely etching the substrate 100 may be used.
The application discloses a multi-channel gas sensor which comprises a substrate, a substrate layer, a heating resistor layer, an isolation medium layer and an interdigital electrode layer; the substrate layer is arranged on the substrate; the heating resistance layer is arranged on the substrate layer; the heating resistor layer comprises a first number of heating resistor arrays; the resistance values of the heating resistor arrays are different; the isolation medium layer is arranged on the heating resistor layer; the interdigital electrode layer is arranged on the isolation medium layer; the interdigital electrode layer comprises a first number of interdigital electrode arrays; the interdigital electrode arrays correspond to the heating resistor arrays one by one and cover the heating resistor arrays. Thus, the obtained multi-channel gas sensor has the advantages of integration and miniaturization.
The above description is only exemplary of the present application and should not be taken as limiting, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (11)
1. A multi-channel gas sensor is characterized by comprising a substrate (100), a substrate layer (1), a heating resistance layer (2), an isolation medium layer (3) and an interdigital electrode layer (4);
the substrate layer (1) is arranged on the substrate (100);
the heating resistance layer (2) is arranged on the substrate layer (1); the heating resistor layer (2) comprises a first number of heating resistor arrays (20); the resistance value of each heating resistor array (20) is different;
the isolation medium layer (3) is arranged on the heating resistor layer (2);
the interdigital electrode layer (4) is arranged on the isolation medium layer (3); the interdigitated electrode layer (4) comprises said first number of interdigitated electrode arrays (40); the interdigital electrode array (40) corresponds to the heating resistor array (20) one by one and covers the heating resistor array (20).
2. Multi-channel gas sensor according to claim 1, characterized in that the substrate layer (1) comprises a first substrate layer (11) and a second substrate layer (12); the first substrate layer (11) is arranged on the base (100); the second substrate layer (12) is arranged on the first substrate layer (11);
the first substrate layer (11) is used for insulation;
the second substrate layer (12) is used for insulating and resisting cold and hot impact caused by rapid temperature rise of the heating resistance layer (2).
3. A multi-channel gas sensor according to claim 1, wherein the heating resistor layer (2) further comprises the first number of markers (21);
the marks (21) correspond to the heating resistor arrays (20) one by one.
4. The multi-channel gas sensor according to claim 1, wherein each of the heating resistor arrays (20) comprises a second number of heating resistors (200);
the resistance values of the heating resistors (200) in each heating resistor array (20) are the same;
the resistance values of the heating resistors (200) in different heating resistor arrays (20) are different.
5. The multi-channel gas sensor according to claim 4, wherein each of the interdigitated electrode arrays (40) comprises the second number of interdigitated electrodes (400);
the interdigital electrodes (400) correspond to the heating resistors (200) one by one and cover the heating resistors (200).
6. Multi-channel gas sensor according to claim 5, characterized in that the heating resistor (200) and the interdigital electrode (400) corresponding to the heating resistor (200) constitute a suspended membrane (5), a cavity (6) being formed in a predetermined area outside the suspended membrane (5).
7. A multi-channel gas sensor according to claim 1, wherein the heating resistor layer (2) further comprises electrode pads (210), the electrode pads (210) being connected to the heating resistor array (20) by traces;
and the position, corresponding to the electrode pad (210), of the isolation medium layer (3) is windowed, and the electrode pad (210) is exposed.
8. A preparation method of a multi-channel gas sensor is characterized by comprising the following steps:
providing a substrate (100);
forming a substrate layer (1) on the substrate (100);
forming a heating resistor layer (2) on the substrate layer (1); the heating resistor layer (2) comprises a first number of heating resistor arrays (20); the resistance value of each heating resistor array (20) is different;
depositing and forming an isolation medium layer (3) on the heating resistor layer (2);
forming an interdigital electrode layer (4) on the isolation medium layer (3); the interdigital electrode layer (4) comprises the first number of interdigital electrode arrays (40); the interdigital electrode array (40) corresponds to the heating resistor array (20) one by one and covers the heating resistor array (20);
and removing the interdigital electrode array (400) and the substrate (100) with a preset depth at a preset area outside the interdigital electrode array (400) through wet etching to obtain the multi-channel gas sensor.
9. Method for producing a multi-channel gas sensor according to claim 8, wherein the forming of a substrate layer (1) on the substrate (100) comprises:
forming a first substrate layer (11) on said base (100) by thermal oxidation;
a second substrate layer (12) is formed on the first substrate layer (11).
10. The method for preparing a multi-channel gas sensor according to claim 8, wherein after the depositing and forming of the isolation medium layer (3) on the heating resistor layer (2) and before the forming of the interdigital electrode layer (4) on the isolation medium layer (3), further comprises:
and etching and windowing the isolation medium layer (3) to expose the electrode pad (210) of the heating resistor layer (2).
11. The method for preparing a multi-channel gas sensor according to claim 8, wherein after the forming of the interdigital electrode layer (4) on the isolation medium layer (3), the removing of the interdigital electrode array (400) and the substrate (100) at a predetermined depth at a predetermined region outside the interdigital electrode array (400) by wet etching to obtain the multi-channel gas sensor further comprises:
and etching the preset area, and removing the substrate layer (1) and the isolation medium layer (3) in the preset area.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211017490.7A CN115266848A (en) | 2022-08-23 | 2022-08-23 | Multi-channel gas sensor and preparation method thereof |
Applications Claiming Priority (1)
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115420339A (en) * | 2022-11-03 | 2022-12-02 | 南京元感微电子有限公司 | Gas and piezoresistive pressure sensor and processing method thereof |
| CN115523961A (en) * | 2022-11-03 | 2022-12-27 | 南京元感微电子有限公司 | Gas and capacitance type pressure sensor and processing method thereof |
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2022
- 2022-08-23 CN CN202211017490.7A patent/CN115266848A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115420339A (en) * | 2022-11-03 | 2022-12-02 | 南京元感微电子有限公司 | Gas and piezoresistive pressure sensor and processing method thereof |
| CN115523961A (en) * | 2022-11-03 | 2022-12-27 | 南京元感微电子有限公司 | Gas and capacitance type pressure sensor and processing method thereof |
| CN115523961B (en) * | 2022-11-03 | 2023-02-28 | 南京元感微电子有限公司 | Gas and capacitance type pressure sensor and processing method thereof |
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