JP7717052B2 - Sensor device and manufacturing method thereof - Google Patents

Description

The present invention relates to a sensor device and a manufacturing method thereof.

The gas sensor described in Non-Patent Document 1 includes a substrate, a gate electrode, a drain electrode, and a source electrode disposed on the substrate, and a graphene layer. This gas sensor has a structure that supports the graphene layer between the drain electrode and the source electrode so that the graphene layer can vibrate, and detects gas components based on the amount of change in the resonant frequency of the graphene layer due to gas adsorption.

S. Lie. et. al., Appl. Phys. Lett., 102, 153101 (2013)

To achieve more sensitive gas detection, the gas sensor's oscillator needs to be able to detect changes in resonant frequency due to gas adsorption with high precision. This means that the oscillator needs to have a high Q value. Furthermore, to identify the vibration mode required for gas detection, the oscillator must not generate any natural vibration modes that interfere with the desired vibration mode.

In view of the above circumstances, the object of the present invention is to provide a sensor device and a method for manufacturing the same that can improve gas detection sensitivity.

A sensor device according to an embodiment of the present invention includes a substrate, an insulating film, a gate electrode, a source electrode, a drain electrode, and a vibrator.
The insulating film is formed on the substrate.
The gate electrode is disposed on the insulating film.
The source electrode has a first conductor layer and a second conductor layer provided on the first conductor layer, and is disposed on the insulating film.
The drain electrode has a third conductor layer and a fourth conductor layer provided on the third conductor layer, and is disposed on the insulating film.
The vibrator has a first end sandwiched between the first and second conductor layers, a second end sandwiched between the third and fourth conductor layers, and a vibrating portion facing the gate electrode.

The oscillator may include a graphene layer.

The oscillator may further include a sensitive film formed on the graphene layer.

The above-mentioned sensitive membrane may be a porous membrane.

The porous membrane may be made of a carbon-based material.

The first to fourth conductor layers may be made of the same type of metal material.

The source electrode may further have an adhesion layer disposed between the first and second conductor layers and in close contact with the vibrator, and the drain electrode may further have an adhesion layer disposed between the third and fourth conductor layers and in close contact with the vibrator.

The gate electrode may be disposed between the substrate and the vibrator.

A method for manufacturing a sensor device according to one aspect of the present invention includes forming a lower electrode layer on a substrate.
A graphene layer is formed on the lower electrode layer.
An upper electrode layer is formed on the graphene layer.
By patterning the lower electrode layer and the upper electrode layer, a source electrode that supports one end of the graphene layer so as to allow the graphene layer to vibrate, a drain electrode that supports the other end of the graphene layer so as to allow the graphene layer to vibrate, and a gate electrode that faces the graphene layer with a predetermined gap in the thickness direction of the substrate are formed.

The present invention can improve gas detection sensitivity.

1 is a schematic diagram showing the configuration of a gas determination system including a sensor device according to an embodiment of the present invention. FIG. 2 is a schematic perspective view showing the configuration of the sensor device. FIG. 2 is a schematic cross-sectional side view of a vibrator in the sensor device. FIG. 2 is a side cross-sectional view of the sensor device. FIG. 10 is a side cross-sectional view of a sensor device according to a comparative example. 6 is a simulation result illustrating a vibration mode of the sensor device shown in FIG. 5 . 5 is a simulation result illustrating a vibration mode of the sensor device shown in FIG. 4. 3A to 3C are schematic cross-sectional views illustrating steps in a method for manufacturing the sensor device. 3A to 3C are schematic cross-sectional views illustrating steps in a method for manufacturing the sensor device. 3A to 3C are schematic perspective views illustrating steps in a method for manufacturing the sensor device. 3A to 3C are schematic perspective views illustrating steps in a method for manufacturing the sensor device.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Gas detection system overview]
Fig. 1 is a schematic diagram showing the configuration of a gas determination system, and Fig. 2 is a schematic diagram showing the configuration of a sensor device 10 that constitutes a part of the gas determination system.

As shown in FIG. 1, the gas determination system 1 includes a sensor device 2, an information processing device 4, a display device 5, and a storage unit 6.
The sensor apparatus 2 includes an accommodation chamber 20 , a sensor device 10 , a UV (ultraviolet) light source 23 , and a heating unit 26 .

The storage chamber 20 houses the sensor device 10, a UV light source 23, and a heating unit 26. The storage chamber 20 has an intake port 21 for drawing in gas from the outside, and an exhaust port 22 for exhausting gas introduced into the storage chamber 20 from the storage chamber 20 to the outside. The intake port 21 is provided with a valve 24 for regulating the flow of gas into the storage chamber 20, and the exhaust port 22 is provided with a valve 25 for regulating the flow of gas from the storage chamber 20 to the outside.

The UV light source 23 emits ultraviolet (UV) light to be irradiated onto the sensor device 10. By irradiating the oscillator 16 of the sensor device 10 with UV light, the oscillator 16 is cleaned. UV irradiation efficiently adsorbs gas onto the oscillator 16. This is thought to be because UV irradiation removes O ₂ , H ₂ O, etc. from the surface of the oscillator 16 (cleaning effect), induces a dynamic equilibrium between adsorption and photo-stimulated desorption of gas molecules on the surface of the oscillator 16, increasing the number of adsorption sites for gas on the oscillator 16 that can be effectively utilized, and accelerates adsorption due to changes in the state of the adsorbed molecules (ionization, etc.).

The heating unit 26 is, for example, a heater, and heats the sensor device 10. Heating the sensor device 10 by the heating unit 26 results in the gas adsorption effect of the vibrator 16.

As shown in FIG. 2, the sensor device 10 has a substrate 11, an insulating film 12, a gate electrode 13, a source electrode 14, a drain electrode 15, and a vibrator 16.

Substrate 11 is typically a silicon substrate, but may also be a semiconductor substrate other than silicon, a glass substrate, etc. Insulating film 12 is formed on substrate 11. Insulating film 12 is typically a silicon oxide film, and when substrate 11 is a silicon substrate, it is a thermal oxide film formed on its surface.

The gate electrode 13, source electrode 14, and drain electrode 15 are formed on the insulating film 12. The gate electrode 13 is disposed between the source electrode 14 and the drain electrode 15. The gate electrode 13, source electrode 14, and drain electrode 15 are typically metal films, and in this embodiment are composed of a laminated film of chromium (Cr) and gold (Au).

The oscillator 16 is disposed between the source electrode 14 and the drain electrode 15 so as to face the gate electrode 13. The oscillator 16 is disposed with a gap therebetween so as not to come into contact with the gate electrode 13. The oscillator 16 is made of a conductive material, and in this embodiment is made of a graphene layer. The graphene layer is made of a single layer film, but may also be a multilayer film. In addition to the graphene layer, the oscillator 16 may also be made of other conductive materials, such as a metal film or a silicon thin film.

As shown in Figure 3, the vibrator 16 is composed of a laminated film of a graphene layer 160 and a sensitive film 17 formed on its surface. The sensitive film 17 is composed of, for example, a material capable of adsorbing the gas to be detected. The material that makes up the sensitive film 17 can be selected arbitrarily depending on the type of gas to be detected, and typically, an organic polymer film (organic polymer film, organic low-molecular-weight film), an organic dye film, or an inorganic film can be used.

The sensitive membrane 17 may be a porous membrane. The porous membrane is formed by decorating the surface of the graphene layer 160 with activated carbon. The material constituting the porous membrane is not limited to activated carbon, and may be any material that is more porous than the graphene layer 160 and has conductive properties similar to those of the graphene layer 160. The conductive material constituting the porous layer 17 may be, for example, a carbon-based material, a conductive polymer, a conductive ceramic, or porous silicon. Preferably, the porous membrane is made of the same carbon-based material as the graphene layer 160. A carbon-based material is a substance whose main component is carbon.

Porous films promote gas adsorption; their porosity increases the adsorption surface area, and they have many dangling bonds, allowing them to adsorb gases efficiently. Because porous films are conductive, they have a larger adsorption surface area and many dangling bonds on the surface, promoting the adsorption of gas molecules, compared to when a non-conductive film is placed on the graphene layer 160 as an adsorption film.

The thickness of the porous film is not particularly limited and may be the same as the thickness of the graphene layer 160, or may be thinner or thicker than the thickness of the graphene layer 160. Typically, the thickness of the graphene layer 160 is 1 nm, and the thickness of the porous film is 1 nm. The porous film is formed so as to cover the entire surface of the graphene layer 160, but is not limited to this and may be formed so as to cover at least a portion of the surface of the graphene layer 160.

The information processing device 4 includes an acquisition unit 41, a determination unit 42, an output unit 43, and a control unit 44. The information processing device 4 controls the driving of the sensor device 10, determines the detected gas component based on the amount of change in the resonant frequency of the vibrator 16, and outputs the determination result.

The control unit 44 resonates the vibrator 16 by inputting a high-frequency signal of a predetermined frequency between the gate electrode 13 and source electrode 14 of the sensor device 10. The acquisition unit 41 acquires a high-frequency signal (drain current) corresponding to the resonant frequency of the vibrator 16 from the drain electrode 15 and converts it into a change in the resonant frequency of the vibrator 16 based on the drain current. The determination unit 42 determines the type or concentration of gas based on the multiple resonant frequency changes acquired by the acquisition unit 41 and by referring to the resonant frequency information stored in the memory unit 6. The output unit 43 outputs the determination result by the determination unit 42 to the display device 5.

When a gas to be detected is introduced into the accommodation chamber 20, the mass of the oscillator 16 changes due to the gas being adsorbed to the oscillator 16, and the resonant frequency of the oscillator 16 decreases based on the amount of change in mass. If the mass of the oscillator 16 before gas adsorption is m, the amount of change in mass of the oscillator 16 due to gas adsorption is Δm, and the resonant frequency of the oscillator 16 is f0, the amount of change Δf in the resonant frequency of the oscillator 16 is calculated by equation (1).
Δf=Δm×f0/(2×m)...(1)

As expressed in equation (1), a smaller mass of the oscillator 16 results in a larger frequency change, so a smaller mass of the oscillator 16 is preferable. In this embodiment, the oscillator 16 is made of carbon, a light element, and graphene, which has excellent electrical and mechanical properties, allowing for highly sensitive detection of frequency changes.

The information processing device 4 acquires resonance frequency information for each of a plurality of different types of gases in advance and stores it in the storage unit 6. The determination unit 42 refers to the resonance frequency information stored in the storage unit 6 to identify and determine the type of gas detected by the sensor device 10.
The output unit 43 outputs the resonance frequency information acquired by the acquisition unit 41 and the determination results such as the type and concentration of gas determined by the determination unit 42 to the display device 5 .

The display device 5 has a display unit, and displays on the display unit the type and concentration of gas output from the information processing device 4. The user can understand the gas determination result by checking the display unit.
Storage unit 6 acquires in advance resonance frequency information for each of a plurality of different types of known gases detected by gas determination system 1 and stores the information as reference data. Storage unit 6 is configured with a storage device such as an HDD (Hard Disk Drive) or semiconductor memory. Storage unit 6 may be located on a cloud server with which information processing device 4 can communicate, or may be provided in information processing device 4 itself.

[Sensor device details]

Next, we will explain the details of the sensor device 10. Figure 4 is a side cross-sectional view of the sensor device 10.

As described above, the vibrator 16 is disposed between the source electrode 14 and the drain electrode 15 so as to face the gate electrode 13. More specifically, the vibrator 16 has a first end 161 supported by the source electrode 14, a second end 162 supported by the drain electrode 15, and a vibrating portion 163 facing the gate electrode 13. The vibrator 16 is disposed with a predetermined gap (e.g., 100 nm) from the gate electrode 13 in the thickness direction of the substrate 11 so that the vibrating portion 163 can vibrate.

On the other hand, the source electrode 14 and the drain electrode 15 have a laminated structure of at least two conductor layers. That is, the source electrode 14 has a first source electrode layer 141 (first conductor layer) provided on the insulating film 12 and a second source electrode layer 142 (second conductor layer) provided on the first source electrode layer 141. Furthermore, the drain electrode 15 has a first drain electrode layer 151 (third conductor layer) provided on the insulating film 12 and a second drain electrode layer 152 (fourth conductor layer) provided on the first drain electrode layer 151.

The first end 161 of the vibrator 16 is sandwiched between the first source electrode layer 141 and the second source electrode layer 142 and is disposed between these electrode layers 141 and 142. The second end 162 of the vibrator 16 is sandwiched between the first drain electrode layer 151 and the second drain electrode layer 152 and is disposed between these electrode layers 151 and 152. The first source electrode layer 141 and the first drain electrode layer 151 are formed with a thickness greater than that of the gate electrode 13, thereby forming the above-mentioned predetermined gap between the vibrating portion 163 of the vibrator 16 and the gate electrode 13.

In this way, in the sensor device 10 of this embodiment, both ends of the vibrator 16 are supported by being sandwiched between the conductor layers (electrode layers) that constitute the source electrode 14 and the drain electrode 15, respectively, thereby enabling the vibrator 16 to be stably held. This makes the vibrator 16 less likely to peel off, suppressing deterioration over time and improving durability of the sensor device 10. An adhesion layer such as chromium (Cr) that adheres closely to the first end 161 of the vibrator 16 may be provided between the first source electrode layer 141 and the second source electrode layer 142. Similarly, an adhesion layer such as Cr that adheres closely to the second end 162 of the vibrator 16 may be provided between the first drain electrode 151 and the second drain electrode 152. This improves adhesion between the vibrator 16 and the source electrode 14 and drain electrode 15, thereby improving durability of the sensor device 10.

The first source electrode layer 141 and the second source electrode layer 142 are preferably made of the same type of metal material. Similarly, the first drain electrode layer 151 and the second drain electrode layer 152 are preferably made of the same type of metal material. This prevents thermal stress from occurring at the interface between the electrode layers due to differences in thermal expansion coefficients, thereby more stably supporting each end 161, 162 of the vibrator 16. "The same type of metal material" refers to the same metal material as well as alloy materials whose main metal material is the same.

Figure 5 is a side cross-sectional view showing the configuration of a sensor device 110 according to a comparative example. In this sensor device 110, a source electrode 114 and a drain electrode 115 are formed on an insulating film 12 of a substrate 11, and a recess 120 for disposing a gate electrode 13 is formed in the insulating film 12 between the source electrode 114 and the drain electrode 115. A vibrator 116 is disposed in the recess 120 so as to face the gate electrode 13, and the upper surfaces of both ends of the vibrator 116 are supported by the lower surfaces of the source electrode 114 and the drain electrode 115, respectively.

Here, the recess 120 is formed by wet etching using the source electrode 114 and the drain electrode 115 as a mask. Because wet etching is isotropic, the recess 120 is formed by under-etching, which erodes part of the interface between the insulating film 12 and the source electrode 114 and the drain electrode 115. This results in regions of the source electrode 114 and the drain electrode 115 that are not supported by the insulating film 12, which serves as the underlying layer, near the ends that support the vibrator 116. Regions of the vibrator 116 that are not supported by the insulating film 12 are also generated, with only the upper surfaces of both ends supported by the source electrode 114 and the drain electrode 115. As a result, the rigidity of the portions supporting both ends of the vibrator 116 is reduced, and the ends of the source electrode 114 and the drain electrode 115 also vibrate in conjunction with the vibration of the vibrator 116, making it difficult to vibrate the vibrator 116 in the desired vibration mode.

6A and 6B show simulation results for evaluating the vibration mode of the sensor device 110 according to the comparative example. Fig. 6A shows the primary vibration mode of the sensor device, and Fig. 6B shows its secondary vibration mode. Here, the thicknesses of the source electrode 114 and the drain electrode 115 were 75 nm, the thickness of the insulating film 12 was 280 nm, the widths of the source electrode 114 and the drain electrode 115 were 3 μm, the opposing distance L1 between the source electrode 114 and the drain electrode 115 (see Fig. 5 ) was 1 μm, and the overhang length L2 of the source electrode 114 and the drain electrode 115 into the recess 120 (see Fig. 5 ) was 2 μm.
In the example shown in the figure, the vibrator 116 has two natural frequencies of 19.7 MHz and 20.2 MHz, and the Q values are 3080 for 19.7 MHz and 1509 for 20.2 MHz.

7A and 7B show simulation results evaluating the vibration mode of the sensor device 10 according to the present embodiment shown in FIG. 7A shows the primary vibration mode of the sensor device, and FIG. 7B shows its secondary vibration mode. Here, the thicknesses of the source electrode 14 and the drain electrode 15 were set to 150 nm (the first source electrode layer 141, the second source electrode layer 142, the first drain electrode layer 151, and the second drain electrode layer 152 were each set to 75 nm), the thickness of the insulating film 12 was set to 280 nm, the widths of the source electrode 14 and the drain electrode 15 were set to 3 μm, and the opposing distance between the source electrode 14 and the drain electrode 15 (the length of the vibrating portion 163 of the vibrator 16) was set to 1 μm.
In the example shown in the figure, the vibrator 16 has two natural frequencies of 26.9 MHz and 77.6 MHz, and the Q values are 10008 for 26.9 MHz and 10009 for 77.6 MHz.

As is clear from the results in Figures 6 and 7, this embodiment achieved a Q value for the vibrator that was more than three times higher than that of the comparative example. The results in the comparative example are thought to be due to the fact that the vibrator was formed by under-etching the insulating film 12, which resulted in insufficient fixation and dissipation of vibration energy to the outside, resulting in a lower Q value for the vibrator 116. In contrast, in this embodiment, both ends of the vibrator 16 are sandwiched between the layers that make up the source electrode 14 and drain electrode 15, and are firmly fixed, which is thought to be why vibration energy does not dissipate to the outside, resulting in a high Q value. As a result, this embodiment can significantly improve gas responsiveness compared to the structure of the comparative example.

Furthermore, in the comparative sensor device 110, the difference between the two natural frequencies was small and the values were close to each other. This indicates that if one of them is selected as the main vibration mode for gas sensing, interference with the other vibration mode is unavoidable. This occurs because the source electrode 114 and drain electrode 115 function as part of the vibrator 116, resulting in the formation of an undesired vibration mode.

In contrast, in the sensor device 10 of this embodiment, the difference between the two natural frequencies is large. This means that when one vibration mode is used for gas sensing, the influence of the other vibration mode is hardly noticeable, indicating that the occurrence of unnecessary vibration modes that can arise due to under-etching is suppressed.

[Method of manufacturing a sensor device]
Next, a method for manufacturing the sensor device 10 of this embodiment configured as described above will be described.

First, as shown in Figure 8(A), an insulating film 12 is formed on a substrate 11. Next, as shown in Figure 8(B), a first resist resin layer 101a is formed on a substrate 110, and a second resist resin layer 101b is formed thereon. The first resist resin layer 101a may be, for example, a methyl methacrylate (MMA) film, and the second resist resin layer 101b may be, for example, a polymethyl methacrylate (PMMA) film.

8(C), the first resist resin layer 101a and the second resist resin layer 101b are exposed and developed using electron beam lithography or the like to form a resist pattern. In this embodiment, an opening pattern is formed in which the pattern width of the second resist resin layer 101b is larger than the pattern width of the first resist resin layer 101a.

Next, as shown in Figure 8(D), a first metal layer 102a is formed on the surface of the second resist resin layer 101b and inside the openings in the second resist resin layer 101b. Then, as shown in Figure 8(E), the first and second resist resin layers 101a, 101b are removed to pattern the first metal layer 102a (lift-off), and a pattern of the first metal layer 102a is formed on the substrate 11.

The first metal layer 102a may be a single layer or a multi-layer structure. In this embodiment, chromium (Cr) with a thickness of approximately 10 nm is formed as the adhesion material, and gold (Au) with a thickness of approximately 130 nm is formed on top of that as the electrode material. The method for forming the first metal layer 102a is not particularly limited, and may be sputtering or vacuum evaporation. In this embodiment, the first metal layer 102a is formed by electron beam evaporation. The first metal layer 102a corresponds to the first source electrode layer 141 and the first drain electrode layer 151 in the sensor device 10 shown in Figure 2.

Next, as shown in Figure 9(A), a third resist resin layer 103a is formed on the substrate 11, and a fourth resist resin layer 103b is formed thereon. The third resist resin layer 103a may be made of, for example, a methyl methacrylate (MMA) film, and the fourth resist resin layer 103b may be made of, for example, a polymethyl methacrylate (PMMA) film.

Next, as shown in Figure 9(B), the third resist resin layer 103a and the fourth resist resin layer 103b are exposed and developed using electron beam lithography or other techniques to form a resist pattern. In this embodiment, an opening pattern is formed in which the opening width of the third resist resin layer 103a is larger than the opening width of the fourth resist resin layer 103b.

Next, as shown in Figure 9(C), a second metal layer 102b is formed on the surface of the fourth resist resin layer 103b and inside the openings in the fourth resist resin layer 103b, and then a sacrificial layer 104 is formed on the surface of the second metal layer 102b. The sacrificial layer 104 is made of, for example, a resist resin.

Then, as shown in Figures 9(D) and 10(A), the third and fourth resist resin layers 103a, 103b and the second metal layer 102b formed on the fourth resist resin layer 103b are removed to pattern (lift off) the second metal layer 102b and the sacrificial layer 104 formed on the second metal layer 102b, and a pattern of the second metal layer 102b and the sacrificial layer 104 is formed on the substrate 11.

The second metal layer 102b may be a single layer or a multi-layer structure. In this embodiment, chromium (Cr) with a thickness of approximately 10 nm is formed as the adhesion material, and gold (Au) with a thickness of approximately 30 nm is formed on top of that as the electrode material. The method for forming the second metal layer 102b is not particularly limited, and may be sputtering or vacuum evaporation. In this embodiment, the second metal layer 102b is formed by electron beam evaporation.

The second metal layer 102b corresponds to the gate electrode 13 in the sensor device 10 shown in Figure 2. Furthermore, the stacked thickness of the second metal layer 102b and the sacrificial layer 104 is typically the same as the thickness of the first metal layer 102a. In this embodiment, since the opening width of the third resist resin layer 103a is larger than the opening width of the fourth resist resin layer 103b, the second metal layer 102b is less likely to come into contact with the side surfaces of the opening in the third resist resin layer 103a, thereby improving the patterning accuracy of the second metal layer 102b during lift-off.

Then, as shown in FIG. 10(B), the laminate of the graphene layer 105 and the protective layer 106 is transferred to the first metal layer 102a. The protective layer 106 is made of, for example, a resist resin. Then, as shown in FIG. 10(C), the protective layer 106 is removed. The graphene layer 105 corresponds to the vibrator 16 in the sensor device 10 of FIG. 2.

10(D), a third metal layer 102c is then formed on the first metal layer 102a. For example, the third metal layer 102c may be formed by forming a resist pattern on the graphene layer 105, forming the third metal layer 102c, and then removing the resist pattern to pattern the third metal layer 102c (lift-off).

The third metal layer 102c faces the first metal layer 102a across the graphene layer 105. The shape of the third metal layer 102c is not particularly limited, and in this embodiment, it is formed with an area smaller than that of the first metal layer 102a. The third metal layer 102c corresponds to the second source electrode 142 and the second drain electrode 152 in the sensor device 10 of Figure 2.

10(E), a fifth resist resin layer 107a is formed on the graphene layer 105 and the third metal layer 102c, and a sixth resist resin layer 107b is formed on top of that. The fifth resist resin layer 107a may be, for example, a polymethyl methacrylate (PMMA) film, and the sixth resist resin layer 107b may be, for example, an AR-N film.

Next, as shown in Figure 10 (F), a resist pattern is formed by exposing and developing only the sixth resist resin layer 107b using electron beam lithography technology or the like.

11A, the fifth resist resin layer 107a and the graphene layer 105 that are not covered with the sixth resist resin layer 107b are removed by dry etching. For example, _O2 plasma is used as the dry etching method. Next, as shown in FIG. 11B, the fifth and sixth resist resin layers 107a and 107b are removed, and as shown in FIG. 11C, the sacrificial layer 104 is removed.

The above describes an embodiment of the present invention, but the present invention is not limited to the above embodiment, and various modifications can of course be made within the scope of the gist of the present invention.

For example, in the above embodiment, a sensor device 10 with a bottom gate structure in which the gate electrode 13 is arranged between the insulating film 12 of the substrate 11 and the vibrator 16 has been described as an example, but this is not limited to this, and the present invention can also be applied to a sensor device with a top gate structure in which the gate electrode is located directly above the vibrator.

REFERENCE SIGNS LIST 1... Gas determination system 4... Information processing device 10... Sensor device 11... Substrate 12... Insulating film 13... Gate electrode 14... Source electrode 15... Drain electrode 16... Vibrator 141... First source electrode (first conductor layer)
142...Second source electrode (second conductor layer)
151...first drain electrode (third conductor layer)
152...Second drain electrode (fourth conductor layer)
161...First end portion 162...Second end portion 163...Vibration section

Claims (9)

A substrate;
an insulating film formed on the substrate;
a gate electrode disposed on the insulating film;
a source electrode having a first conductor layer and a second conductor layer provided on the first conductor layer and disposed on the insulating film;
a drain electrode having a third conductor layer and a fourth conductor layer provided on the third conductor layer and disposed on the insulating film;
a vibrator having a first end portion sandwiched between the first and second conductor layers, a second end portion sandwiched between the third and fourth conductor layers, and a vibrating portion facing the gate electrode with a predetermined gap in a thickness direction of the substrate ;
Equipped with
The gate electrode is disposed between the source electrode and the drain electrode, and the first conductor layer and the third conductor layer have a thickness greater than that of the gate electrode.
Sensor device. The sensor device according to claim 1 ,
The sensor device, wherein the oscillator includes a graphene layer. The sensor device according to claim 2,
The sensor device, wherein the oscillator further includes a sensitive film formed on the graphene layer. The sensor device according to claim 3,
The sensor device, wherein the sensitive membrane is a porous membrane. The sensor device according to claim 4,
The porous film is a carbon-based material. The sensor device according to any one of claims 1 to 5,
The first to fourth conductor layers are made of the same metal material. The sensor device according to any one of claims 1 to 6,
the source electrode further includes an adhesion layer disposed between the first and second conductor layers and in close contact with the vibrator;
The drain electrode further includes an adhesion layer disposed between the third and fourth conductor layers and in close contact with the vibrator. The sensor device according to any one of claims 1 to 6,
The sensor device, wherein the gate electrode is disposed between the substrate and the oscillator. A lower electrode layer is formed on the substrate;
forming a graphene layer on the lower electrode layer;
forming an upper electrode layer on the graphene layer;
patterning the lower electrode layer and the upper electrode layer to form a source electrode that supports one end of the graphene layer so as to be able to vibrate the graphene layer, a drain electrode that supports the other end of the graphene layer so as to be able to vibrate the graphene layer, and a gate electrode that faces the graphene layer with a predetermined gap in a thickness direction of the substrate ;
The gate electrode is disposed between the source electrode and the drain electrode, and a part of the source electrode and a part of the drain electrode located between the substrate and the graphene layer are formed to have a thickness greater than that of the gate electrode.
A method for manufacturing a sensor device.