KR101104306B1 - Sensors for detecting temperature and multi gas and methed for manufacturing the same - Google Patents

Abstract

In the present disclosure, providing an insulating substrate; Forming a temperature sensitive material layer on the insulating substrate; Patterning the temperature sensitive material layer to form a temperature sensitive film; Forming an insulating film on the temperature sensitive film; Forming a conductive oxide layer on the heat transfer film; Patterning the conductive oxide film to form a plurality of electrode pattern arrays; Forming a plurality of gas sensitive films on the plurality of electrode pattern arrays in multiple layers; And selectively etching the plurality of gas sensitive films to form a gas sensitive film array on each of the plurality of electrode pattern arrays, the gas sensitive film array comprising at least one gas sensitive film. Provide a method.

Oxide temperature sensor, gas sensor, oxide insulating film, conductive oxide, array

Description

Temperature and Multi-Gas Sensing Sensor Arrays and Manufacturing Method Thereof {SENSORS FOR DETECTING TEMPERATURE AND MULTI GAS AND METHED FOR MANUFACTURING THE SAME}

The present invention relates to an array of oxide-based temperature and multiple gas sensitive sensor arrays and a method of manufacturing the same.

In general, a gas sensor based on an oxide semiconductor detects a test gas by using a change in electrical conductivity generated when the test gas contacts a sensor surface. However, the conventional gas sensor has a problem that it does not provide sufficient information about the type, molecular weight, and the like of the test gas. For example, an n-type oxide gas sensor has a thinner depletion layer on the surface of the sensor when it comes into contact with a reducing gas, which increases its conductivity. Although it is possible to distinguish whether or not it is a gas, there was a limit that the type and molecular weight of a specific test gas cannot be confirmed.

In addition, conventional gas sensors typically exhibit maximum operating characteristics at temperatures around 200 to 500 ° C. rather than room temperature, and show a large difference in sensitivity depending on the temperature. It was inconvenient to acquire simultaneously. In addition, although a precious metal such as platinum, which is relatively stable with respect to temperature due to the operating temperature of the conventional gas sensor, is used as an electrode material of an oxide gas sensor, the sensor may be used in an internal environment or an extreme environment where a metal electrode cannot be applied. There was also a problem that can not be used.

Even in a process for manufacturing a gas sensor, a conventional gas sensor manufacturing process opens and detects only a part of electrode patterns in independently forming different sensing films on a pattern array of electrodes of a noble metal to give selectivity for a test gas. There was the inconvenience of having to execute the process of forming the film several times. For example, in order to form four arrays, it is necessary to perform four sensing film forming processes.

Accordingly, the present invention provides a temperature and multiple gas-sensitive sensor array and a method for manufacturing the same, which can simultaneously obtain information on temperature and gas, and can be easily applied to an internal environment or an extreme environment.

According to one embodiment, the sensor array comprises an insulating substrate; A temperature sensitive film formed on the insulating substrate; An insulating film disposed on the temperature sensitive film; A plurality of electrode pattern arrays disposed on the insulator; And a plurality of gas sensitive film arrays. In an embodiment, each of the plurality of gas sensitive film arrays may be disposed on a corresponding array of the plurality of electrode pattern arrays and include at least one gas sensitive film.

In another embodiment, a method of fabricating a sensor array includes providing an insulating substrate; Forming a temperature sensitive material layer on the insulating substrate; Patterning the temperature sensitive material layer to form a temperature sensitive film; Forming an insulating film on the temperature sensitive film; Forming a conductive oxide layer on the heat transfer film; Patterning the conductive oxide film to form a plurality of electrode pattern arrays; Forming a plurality of gas sensitive films on the plurality of electrode pattern arrays in multiple layers; And selectively etching the plurality of gas sensitive films to form a gas sensitive film array on each of the plurality of electrode pattern arrays. According to one embodiment, the gas sensitive film array may be formed to include at least one gas sensitive film.

The temperature and gas sensitive sensor array according to the present invention is composed of an oxide and can be easily applied to an internal environment or an extreme environment, and can simultaneously obtain information on temperature and gas. In addition, the method of manufacturing a temperature and gas sensitive sensor array according to the present invention, by forming a multi-layer thin film structure in a series of processes and applying a selective etching method to form a gas sensitive film array, a sensor having a gas sensitive film of several layers Allows the array to be manufactured simply.

Each component and the arrangement relationship between the components shown in the drawings or described below may be modified in various configurations as an example. Therefore, it should be understood that each embodiment described in detail with reference to the drawings is not intended to limit the scope of the claims, but merely to describe representative embodiments of the various forms possible. Hereinafter, a detailed description will be made by using the accompanying drawings and the reference numbers indicated therein for clarity of understanding, and the parts denoted by the same reference numerals in the drawings represent the same configuration.

FIG. 1A illustrates a top view of a temperature and multiple gas sensitive sensor array 100 (hereinafter referred to as a “sensor array”) in accordance with one embodiment of the present application, and FIGS. 1B and 1C show the sensor shown in FIG. 1A A cross-sectional view of the array 100 is cut in the aa 'direction and the bb' direction, respectively.

In an exemplary embodiment, the sensor array 100 may include an insulating substrate 110, a temperature sensitive film 120 for obtaining temperature information, an insulating film 130, and an electrode pattern array as illustrated in FIGS. 1B and 1C. 142, 144, 146, 148 and gas sensitive film arrays 152, 154, 156, 158 for gas sensing.

In one embodiment, the insulating substrate 110 may be made of a material having electrical insulation, such as alumina or silicon oxide.

In one embodiment, the temperature sensitive film 120 may be disposed on the insulating substrate 110. In one embodiment, the temperature sensitive film 120 is connected to each other at the connection portion 222 and the connection portion 222 and extend in parallel with a predetermined distance from the connection portion 222, as shown in FIG. It may include a first extension 224a and a second extension 224b. In addition, the temperature sensitive film 120 is perpendicular to the extending direction of the first extension part 224a and the second extension part 224b, and extends in opposite directions to each other, and the first end part 226a and the second end part 226b. ) May be further included. However, it will be appreciated that the shape of the temperature sensitive film 120 is not limited thereto and may be freely deformed.

In one embodiment, the temperature sensitive film 120 may be disposed in the middle portion of the insulating substrate 110, as shown in FIG. However, it should be noted that the temperature sensitive film 120 is not limited to such an arrangement, and may be freely disposed on the insulating substrate 110.

In one embodiment, the temperature sensitive film 120 is an oxide thermoelectric capable of measuring the temperature change by the electromotive force change, such as a conventional thermistor material or cobalt oxide-based material that can measure the temperature change by the resistance change, such as barium titanate It may be made of a material.

In an exemplary embodiment, the insulating layer 130 may be formed on the temperature sensitive layer 120 to electrically separate the electrode pattern arrays 142, 144, 146 and 148 and the temperature sensitive layer 120, which will be described in detail below. In an embodiment, the insulating layer 130 is disposed to cover the connection portion 222, the first extension portion 224a, and the second extension portion 224b of the temperature sensitive film 120, as shown in FIG. 1A. Can be. In one embodiment, the insulating film 130, as shown in FIG. 3, the first end 226a of the temperature sensitive film 120 such that the first end 226a and the second end 226b are exposed to the outside. And the second end 226b may not be covered.

In one embodiment, the insulating film 130 may have a thickness of about 1 μm or less. However, the thickness of the insulating layer 130 is not limited thereto, and it will be appreciated that the thickness of the insulating layer 130 can be freely modified in consideration of the sensitivity of the temperature response of the sensor array 100 and the size of the entire device.

In an embodiment, the electrode pattern arrays 142, 144, 146, and 148 may be disposed on the insulating layer 130. Referring to FIG. 3, each of the electrode pattern arrays 142, 144, 146, and 148 may have two comb-shaped electrodes (IDE: 340a, 340b), and electrodes 340a, 340b for measuring electrical signals such as resistance or voltage. The contact pads 342a and 342b may be connected to each other. In one embodiment, the two comb-shaped electrodes 340a and 340b included in one electrode pattern array 142, 144, 146 and 148 may be disposed to face each other and cross each other. In one embodiment, the spacing d between the combs of the electrodes 340a and 340b may be approximately 20 μm to 200 μm. However, the shape, arrangement, and spacing between the comb teeth of the electrode pattern arrays 142, 144, 146, and 148 are not limited thereto, and the change in resistance generated in the gas sensitive film arrays 152, 154, 156, and 158 located on the upper portion, which will be described in detail below, may be detected. It will be appreciated that it is free to deform within the scope of the structure.

As illustrated in FIG. 3, four electrode pattern arrays 142, 144, 146, and 148 may be disposed on the insulating layer 130, but the number of electrode pattern arrays 142, 144, 146, and 148 disposed on the insulating layer 130 is not limited thereto. As will be described in detail below, it should be appreciated that the number may be four or more, depending on the number of gas sensitive film arrays 152, 154, 156, and 158.

In an exemplary embodiment, the electrode pattern arrays 142 and 146 may have a connection portion 222, a first extension portion 224a, and a second extension portion 224b of the temperature sensitive layer 120 disposed under the insulating layer 130. It may be disposed to face the other electrode pattern arrays 144 and 148. In one embodiment, the electrode pattern arrays 142, 144, 146, and 148 may be formed of indium tin oxide (ITO), n-type zinc oxide, or the like.

In one embodiment, the gas sensitive film arrays 152, 154, 156, and 158 may be disposed on the electrode pattern arrays 142, 144, 146, and 148, respectively. In one embodiment, the gas sensitive membrane arrays 152, 154, 156, 158 may include one or more gas sensitive membranes 162, 164, 166, 168, and the number of gas sensitive membranes 162, 164, 166, 168 that each of the gas sensitive membrane arrays 152, 154, 156, 158 is different from each other. Can be. For example, as shown in FIGS. 1B and 1C, the gas sensitive film array 152 includes one gas sensitive film 162, and the gas sensitive film array 154 is two gas sensitive stacked one after another. Films 162, 164, and the gas sensitive film array 156 includes three gas sensitive films 162, 164, 166, which are sequentially stacked, and gas sensitive film array 158, four gas sensitive films 162, 164, 166, 168, which are sequentially stacked. It may include.

In an embodiment, the gas sensitive films 162, 164, 166, and 168 included in the gas sensitive film arrays 152, 154, 156, and 158 may be formed of metal oxide semiconductor materials having different gas sensitive characteristics. For example, the gas sensitive film 162 is made of tin oxide, the gas sensitive film 164 is made of titanium oxide, the gas sensitive film 166 is made of zinc oxide, and the gas sensitive film 168 is made of It may be composed of tungsten oxide. In this case, since the uppermost gas sensitive films 162, 164, 166, and 168 exposed to the outside from the gas sensitive film arrays 152, 154, 156, and 158 may have different gas sensitive characteristics, it is possible to detect a plurality of gases. For example, tin oxide, titanium oxide, zinc oxide, tungsten oxide, and the like, when the test gas is H2, CO, CO2, NOx, CH4, etc., each exhibits different response characteristics for each test gas. It is possible to extract information on the selectivity of the test gas from the response characteristic. The material constituting the gas sensitive films 162, 164, 166, and 168 is not limited thereto, and it should be understood that various other materials having gas sensitive properties may be used.

In an embodiment, the number of gas sensitive film arrays 152, 154, 156, and 158 included in the sensor array 100 may be determined according to the number of types of test gases. In addition, the number of electrode pattern arrays 142, 144, 146, and 148 may be determined according to the determined number of gas sensitive film arrays 152, 154, 156, and 158.

Hereinafter, a method of manufacturing an oxide-based temperature and multiple gas sensitive sensor array 100 according to an embodiment of the present invention described with reference to FIGS. 1 to 3 will be described with reference to FIGS. 4 to 10.

Figure 4 is a flow chart illustrating each step of the method for manufacturing an oxide-based temperature and multiple gas sensitive sensor according to the present invention.

First, as shown in FIG. 5, an insulating substrate 500 is provided (S400). In an embodiment, the insulating substrate 500 may be made of a material having electrical insulation, such as alumina or silicon oxide, similarly to the insulating substrate 110 described above.

Next, as shown in FIG. 6, a temperature sensitive oxide layer 600 is deposited on the insulating substrate 500 (S402). In one embodiment, the temperature sensitive oxide layer 600 may be comprised of a conventional thermistor material, barium titanate or a cobalt oxide based material that is an oxide thermoelectric material. In one embodiment, the temperature sensitive oxide layer 600 may be deposited using conventional deposition methods such as sputtering or PLD.

Next, patterning is performed on the temperature sensitive oxide layer 600 deposited on the insulating substrate 500 to form a temperature sensitive film 700 as shown in FIG. 7 (S404).

The temperature sensitive oxide layer 600 may be patterned such that the temperature sensitive film 700 has the same shape as the temperature sensitive film 120 described above with reference to FIG. 2. For example, as illustrated in FIG. 7, the temperature sensitive film 700 is connected to each other at the connecting portion 702 and the connecting portion 702 and extends in parallel with a predetermined distance from the connecting portion 702. 704a and second extension portion 704b, and first end portions 706a and second perpendicular to the extension directions of the first extension portion 704a and the second extension portion 704b, and extending in opposite directions. Remaining portions on the temperature sensitive oxide layer 600 except for the connections 702, the first and second extensions 704a and 704b and the first and second ends 706a and 706b to be configured as the ends 706b. A photosensitive material such as silver photoresist or the like can be used to expose and etch. However, as described above, the temperature sensitive film 700 is not limited to the shape shown in FIG. 7 and may have a freely deformed shape, and according to the shape of the temperature sensitive film 700, the temperature sensitive oxide layer 600 may be used. Can be formed by exposing and etching a portion of the substrate.

In one embodiment, the temperature sensitive film 700 may be formed by performing etching on the temperature sensitive oxide layer 600 using dry etching or chemical etching using a method such as an ion beam.

Next, an insulating film 800 is formed on the temperature sensitive film 700 (S406). In one embodiment, the shape and arrangement of the insulating film 800 may be applied in the same manner as the shape and arrangement of the insulating film 130 described above with reference to FIG. 3. In one embodiment, the insulating film 800 may be formed according to conventional methods such as sputtering or pulsed laser deposition.

Next, as shown in FIG. 9, the conductive oxide layer 900 is formed on the insulating film 800 (S408). In one embodiment, the conductive oxide layer 900 may be made of a conductive oxide, such as indium tin oxide (ITO), n-type zinc oxide, or the like as described above. In one embodiment, electrode oxide layer 900 may be deposited using conventional thin film formation processes, such as sputtering, pulsed laser deposition, and the like.

Next, a patterning process is performed on the conductive oxide layer 900 to form electrode pattern arrays 1002, 1004, 1006, and 1008 (S410).

As illustrated in FIG. 10, four electrode pattern arrays 1002, 1004, 1006, and 1008 may be formed by patterning the conductive oxide layer 900. In one embodiment, the four electrode pattern arrays 1002, 1004, 1006, and 1008 are connected to the connection portion 702 of the temperature sensitive film 700 in which the two electrode pattern arrays 1002, 1006 are disposed under the insulating film 800. ), And the first and second extension portions 704a and 704b may be disposed to face the other two electrode pattern arrays 1004 and 1008, respectively.

In one embodiment, each of the electrode pattern arrays 1002, 1004, 1006, and 1008 includes two comb-shaped electrodes 1010a and 1010b, similarly to the electrode pattern arrays 142, 144, 146, and 148 described above with reference to FIG. 3. The two electrodes 1010a and 1010b may be formed to face each other and the comb teeth of each of the electrodes 1010a and 1010b may be alternately disposed. In one embodiment, the spacing between the comb teeth arranged alternately of the electrodes 1010a, 1010b may be formed to be approximately 20㎛ ~ 200㎛. In addition, in one embodiment, each electrode pattern array 1002, 1004, 1006, and 1008 includes contact pads 1012a and 1012b connected to the electrodes 1010a and 1010b to enable measurement of an electrical signal such as resistance or voltage. It can be formed to.

However, as described above, the shape, arrangement, and spacing between the comb teeth of the electrode pattern arrays 1002, 1004, 1006, and 1008 are not limited thereto, and the gas sensitive film arrays 1102, 1104, 1106, It should be noted that the structure of 1108 may be freely formed within the range of the structure capable of detecting a change in resistance. In addition, the number of electrode pattern arrays 1002, 1004, 1006, and 1008 included in the oxide electrode 1000 may be positioned on the upper portion of each electrode pattern array 1002, 1004, 1006, and 1008, which will be described below. It should be appreciated that the number may be determined according to the number of gas sensitive film arrays 1202, 1204, 1206, and 1208.

In an embodiment, the electrode pattern arrays 1002, 1004, 1006, and 1008 may be dry-etched by ion milling or the like with a portion of the conductive oxide layer 900 opened using a photoresist such as a photoresist. Or using conventional etching techniques such as chemical etching.

Next, gas sensitive films 1102, 1104, 1106, and 1108 are formed on the electrode pattern arrays 1002, 1004, 1006, and 1008 (S412). In one embodiment, on the electrode pattern arrays 1002, 1004, 1006, 1008, four gas sensitive films 1102, 1104, 1106, 1108 may be formed, as shown in FIG. 11, and four electrodes The stacks may be sequentially stacked on the electrode pattern arrays 1002, 1004, 1006, and 1008 to cover the pattern arrays 1002, 1004, 1006, and 1008. However, the number of gas sensitive films 1102, 1104, 1106, and 1108 formed on the electrode pattern arrays 1002, 1004, 1006, and 1008 is not limited thereto, and four may be selected depending on the number of test gas types to be detected. It may be more or less. In this case, as described above, the number of electrode pattern arrays 1002, 1004, 1006, and 1008 formed on the insulating film 800 may also vary according to the number of gas sensitive films 1102, 1104, 1106, and 1108. .

In one embodiment, each gas sensitive film 1102, 1104, 1106, 1108, as described above, may be composed of oxides having different sensitivity depending on the temperature or the test gas. For example, the gas sensitive films 1102, 1104, 1106, and 1108 may be composed of oxides such as zinc oxide, titanium oxide, tungsten oxide, or tin oxide, respectively. However, it will be appreciated that the materials forming the gas sensitive films 1102, 1104, 1106, and 1108 are not limited thereto, and other materials having gas sensitive properties may be used.

In one embodiment, the stacked gas sensitive films 1102, 1104, 1106, and 1108 may have a material structure that increases the surface area and shortens the diffusion distance, such as a nanowire structure or a three-dimensional embossed structure, in order to increase sensor sensitivity. It can be formed to have.

In an embodiment, the gas sensitive films 1102, 1104, 1106, and 1108 may be formed using a vacuum method such as sputtering or a pulse laser method having multiple channels, or a wet method using a sol-gel method. However, it should be noted that the method of forming the gas sensitive films 1102, 1104, 1106, and 1108 is not limited thereto, and may be formed through various methods capable of forming a multilayer structure.

Next, the gas sensitive films 1102, 1104, 1106, and 1108 are selectively etched to form gas sensitive film arrays 1202, 1204, 1206, and 1208 on the electrode pattern arrays 1002, 1004, 1006, and 1008, respectively. (S414). In one embodiment, as shown in FIG. 12, the gas sensitive film array 1202 includes a gas sensitive film 1102, and the gas sensitive film array 1204 turns the gas sensitive films 1102 and 1104. Gas sensitive membrane array 1206 includes gas sensitive membranes 1102, 1104, and 1106 in turn, and gas sensitive membrane array 1208 sequentially turns gas sensitive membranes 1102, 1104, 1106, and 1108. The gas sensitive films 1102, 1104, 1106, and 1108 may be selectively etched to be included as they are.

As described above, each of the gas sensitive film arrays 1202, 1204, 1206, and 1208 includes the gas sensitive films 1102, 1104, 1106, and 1108 having different gas sensitivity as the uppermost layers. Therefore, it is possible to detect a plurality of gases.

As described above, those skilled in the art to which the present invention pertains or those skilled in the art can understand that the present invention can be variously modified and changed without departing from the technical matters and scope of the present invention described in the claims. There will be. Therefore, the above-described details are not to be considered as limiting, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention.

1A shows a top view of a sensor array, in accordance with one embodiment of the present invention, and FIGS. 1B and 1C show cross-sectional views taken along the aa 'and bb' directions of the sensor array shown in FIG. 1A, respectively.

2 illustrates a temperature sensitive film disposed on an insulating substrate of a sensor array, according to one embodiment of the invention.

3 shows an electrode pattern array formed over an insulating film.

4 is a flowchart illustrating each step of the sensor array manufacturing method according to an embodiment of the present invention.

5 to 12 are diagrams illustrating a sensor array manufacturing method according to an embodiment of the present invention.

Claims (15)

In the sensor array, Insulating substrate; A temperature sensitive film formed on the insulating substrate; An insulating film disposed on the temperature sensitive film; A plurality of conductive oxide electrode pattern arrays disposed on the insulating film; And A plurality of multi-layer gas sensitive film arrays, each of the plurality of gas sensitive film arrays disposed on a corresponding array of the plurality of electrode pattern arrays and comprising at least one gas sensitive film; Sensor array comprising a. The method of claim 1, And a gas sensitive film, which is a top layer of the gas sensitive films included in each of the plurality of multi-layered gas sensitive film arrays, is formed of different gas sensitive materials. The method of claim 1, And the temperature sensitive film includes a connection portion and an extension portion extending from the connection portion, wherein the connection portion and the extension portion are disposed at an intermediate portion of the insulating substrate. The method of claim 3, Some electrode pattern arrays of the plurality of electrode pattern arrays are disposed on the insulating film so as to face another electrode pattern array with the extension portion of the temperature sensitive film disposed below the insulating film interposed therebetween. The method of claim 1, The temperature sensitive film comprises a cobalt oxide-based thermoelectric material or a barium titanate-based thermistor material. The method of claim 5, And the temperature sensitive film is cobalt oxide or barium titanate. The method of claim 1, And the temperature sensitive film, the insulating film, the electrode pattern array, and the gas sensitive film array comprise an oxide. As a sensor array manufacturing method, Providing an insulating substrate; Forming a temperature sensitive material layer on the insulating substrate; Patterning the temperature sensitive material layer to form a temperature sensitive film; Forming an insulating film on the temperature sensitive film; Forming a conductive oxide layer on the heat transfer film; Patterning the conductive oxide layer to form a plurality of electrode pattern arrays; Forming a plurality of gas sensitive films on the plurality of electrode pattern arrays in multiple layers; And Selectively etching the plurality of gas sensitive films to form a gas sensitive film array on each of the plurality of electrode pattern arrays, the gas sensitive film array including at least one gas sensitive film Sensor array manufacturing method comprising a. The method of claim 8, And said plurality of gas sensitive films are comprised of different gas sensitive materials. 10. The method of claim 9, Selectively etching the plurality of gas sensitive films to form a gas sensitive film array on each of the plurality of electrode pattern arrays, wherein the gas sensitive film arrays respectively formed on the plurality of electrode pattern arrays have different numbers of gases. Selectively etching the plurality of gas sensitive films to include a sensitive film. The method of claim 8, The temperature sensitive film comprises a cobalt oxide-based thermoelectric material or a barium titanate-based thermistor material. The method of claim 11, And the temperature sensitive material layer is cobalt oxide or barium titanate. The method of claim 8, And the temperature sensitive material layer, the insulating film, the conductive oxide layer, and the gas sensitive film each comprise an oxide. The method of claim 8, The forming of the temperature sensitive film by patterning the temperature sensitive material layer may include: connecting the temperature sensitive film to a connection part and an extension part extending from the connection part, wherein the connection part and the extension part are disposed at an intermediate portion of the insulating substrate. Patterning the layer of sensitive material. The method of claim 14, Patterning the conductive oxide layer to form a plurality of electrode pattern arrays, wherein some of the electrode pattern arrays of the plurality of electrode pattern arrays are disposed on the insulating film with the extension part of the temperature sensitive film disposed under the insulating film interposed therebetween. Patterning the conductive oxide layer to face the other electrode pattern array.

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