JP2001153836A - Integrated ion sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated ion sensor capable of increasing its accuracy while reducing the size of the sensor as a whole. SOLUTION: A pH sensor 30, a temperature sensor 40, a flow rate sensor 50 are integrated on a base board 1 formed of a silicon substrate provided with a hypochlorous acid ion sensor detecting a hypochlorous acid ion. The hypochlorous acid sensor 20 is provided with a platinum electrode 11 and a silver/silver chloride electrode 10 formed separately from each other on the main surface side of the substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated ion sensor in which another sensor is integrated on a substrate on which an ion sensor for detecting a specific ion is formed.

[0002]

2. Description of the Related Art An ion sensor is characterized in that a specific ion concentration in a solution can be selectively quantified, and is used in a wide range of fields such as a specific ion concentration monitor, water quality analysis, and medical treatment. In particular, in the field of water quality analysis, it is applied to quantitative measurement of ions (for example, hydrogen ions, chloride ions, calcium ions, etc.) contained in water.
As an application example, there is a chlorine sensor used in a water purification system. Chlorine This type of sensor, hypochlorite ions (ClO ^-), which is one of the residual chlorine contained in tap water
Is measured, and the concentration of hypochlorite ion can be measured by a polarographic method using a silver / silver chloride electrode and a platinum electrode. In this polarographic method, when the following reaction occurs between the platinum electrode and the silver / silver chloride electrode in the measurement solution, the concentration is proportional to the hypochlorite ion concentration in the solution from the silver / silver chloride electrode to the platinum electrode. Since a large amount of current flows, the concentration of hypochlorite ion can be known by measuring this current. Platinum electrode: HClO + e ⁻ → 1 / 2H ₂ + ClO ⁻ silver / silver chloride electrode: Ag + ClO ⁻ → AgCl + 1 / 2O ₂
+ E ^-

[0003]

However, the detection accuracy of the ion sensor depends on the pH, temperature,
It is known that it is affected by the flow velocity and the like, and there is a problem that it is impossible to accurately detect the hypochlorite ion concentration under the influence of the influence. In order to solve this kind of problem, a hypochlorite ion sensor and an individual component p
There has been proposed a system configured by combining another sensor such as an H sensor, a temperature sensor, a flow sensor, and a signal processing circuit for correcting an output signal of a hypochlorite ion sensor in accordance with an output signal of the other sensor. However, there are problems that the number of components is large, the system becomes large, and signal processing becomes complicated.

The present invention has been made in view of the above circumstances, and has as its object to reduce the size of a system in which a hypochlorite ion sensor is combined with another sensor and a signal processing circuit while reducing the size of hypochlorite. An object of the present invention is to provide an integrated ion sensor capable of measuring the concentration of an acid ion with high accuracy.

[0005]

According to a first aspect of the present invention, at least one of a pH sensor, a temperature sensor, and a flow rate sensor is provided on a substrate of an ion sensor for detecting specific ions. It is characterized by being integrated, so that the number of components can be reduced when configuring the system, and the accuracy of detecting the specific ions can be improved while reducing the size of the system.

According to a second aspect of the present invention, in the first aspect of the invention, the ion sensor is a hypochlorite ion sensor having a platinum electrode and a silver / silver chloride electrode. Accuracy can be improved.

According to a third aspect of the present invention, in the first or second aspect, a signal processing circuit for correcting an output signal of the ion sensor according to an output signal of the other sensor is integrated on the substrate. Therefore, the size of the system can be further reduced.

According to a fourth aspect of the present invention, in the first or second aspect, the substrate is a silicon substrate,
An insulating film for insulating between the sensors is provided, and the insulating film is
Since it is made of the COS oxide film, the insulation between the sensors can be enhanced, and as a result, the detection accuracy of hypochlorite ions can be further improved.

According to a fifth aspect of the present invention, in the first or second aspect of the present invention, the substrate is made of an SOI substrate, so that the insulation between the sensors can be enhanced, and as a result, hypochlorite ion Can be further improved.

According to a sixth aspect of the present invention, in the second aspect of the invention, the flow rate sensor comprises a heater made of platinum and a temperature detecting section made of platinum, and the temperature detecting section and a platinum sensor of the hypochlorite ion sensor. Since the electrodes are also used, the size of the system can be further reduced.

According to a seventh aspect of the present invention, in the first or second aspect of the present invention, the flow rate sensor includes a heater made of a diffusion resistor. The size of the sensor can be reduced, and as a result, the size of the system can be reduced.

According to an eighth aspect of the present invention, in the first or second aspect of the present invention, the flow sensor has a heater made of polysilicon. Can be reduced,
As a result, the size of the system can be reduced.

According to a ninth aspect of the present invention, in the first or second aspect of the present invention, the flow rate sensor has a recess formed on the back side of the substrate, so that the heat insulation of the flow rate sensor is improved. Low power consumption can be achieved.

According to a tenth aspect of the present invention, in the first to ninth aspects of the present invention, the flow rate sensor and the pH sensor each have a recess formed on the back side of the substrate.
Since the pH sensor is a back-gate type pH sensor, the heat insulation of the flow sensor is improved, and the insulation of the pH sensor can be enhanced by providing an electrode of the pH sensor on the back side of the pH sensor. For higher accuracy,
In addition, the recess of the flow sensor and the recess of the pH sensor can be formed at the same time, and the manufacturing process can be simplified.

According to an eleventh aspect of the present invention, in the first or the second aspect of the present invention, the temperature sensor includes a diode made of polysilicon as a temperature detecting portion. The size of the temperature detecting section can be reduced, and as a result, the size of the system can be reduced.

According to a twelfth aspect of the present invention, in the second aspect of the present invention, the pH sensor has a light-shielding film made of silver on its surface. The reflectance of the light-shielding film is improved as compared with the case where the light-shielding film is made of aluminum or polysilicon, so that the light leakage current of the pH sensor can be reduced and the pH sensor can be made more precise. Since it can be formed simultaneously with the silver / silver chloride electrode of the hypochlorite ion sensor, there is no need to add a separate step for forming a light-shielding film, and an apparatus for forming a light-shielding film is separately provided. Since there is no need to prepare, the manufacturing process can be simplified and the manufacturing cost can be reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) As shown in FIGS.
The sensor 30, the temperature sensor 40, and the flow rate sensor 50 are integrated on a substrate 1 formed of a silicon substrate on which a hypochlorite ion sensor 20 for detecting hypochlorite ions is formed.

Here, the hypochlorite ion sensor 20 is
The substrate 1 includes a platinum electrode 11 and a silver / silver chloride electrode 10 formed separately from each other on the main surface side of the substrate 1.

In the pH sensor 30, a drain region 3 and a source region 4 are formed on the main surface side of the substrate 1 with a space therebetween, and a silicon oxide film (SiO ₂ ) is formed on a channel portion between the regions 3 and 4. An ion-sensitive film 7a made of a silicon nitride film (Si ₃ N ₄ ) is formed via a gate insulating film 2a made of. Here, the pH sensor 30 uses hydrogen ions (H ⁺ ) as measurement ions. A drain electrode 5 made of polysilicon is formed on the drain region 3.
b, and a source electrode 5c made of polysilicon is formed on the source region 4.
c is connected to pads 18 made of aluminum via wires 5a 5a made of polysilicon and wires 8a 8a made of aluminum, respectively.
The pH sensor 30 has a channel stopper 13 formed on the main surface side of the substrate 1.

In the temperature sensor 40, a temperature detecting portion 41 formed of a heater having a planar shape and a broken shape is formed on the main surface side of the substrate 1, and both ends of the temperature detecting portion 41 are formed of wiring 5a, It is connected to pads 18 made of aluminum via wirings 8a made of aluminum and 5a. Here, the heater constituting the temperature detecting section 41 is formed of platinum.

In the flow rate sensor 50, a heater 51 having a planar shape with a broken shape is formed on the main surface side of the substrate 1, and a temperature detecting portion 52, 5 with a planar shape with a broken shape.
3 are formed on both sides of the heater 51 on the main surface side of the substrate 1 (left and right of the heater 51 in FIG. 1). Here, each of the temperature detectors 52 and 53 is formed of platinum. Both ends of the heater 51 are connected to pads 18 made of aluminum via wirings 5a made of polysilicon and wirings 8a made of aluminum, respectively. Both ends of each of the temperature detectors 52 and 53 are also connected to the wirings 5a and 5a made of polysilicon and the wiring 8 made of aluminum.
a, 18 made of aluminum via a, 8a
8 is connected.

Hereinafter, a method of manufacturing the integrated ion sensor according to the present embodiment will be briefly described.

First, a silicon oxide film (SiO ₂ ) 2 is formed on the entire surface of the main surface (upper surface in FIG. 2) of the substrate 1. After that, the silicon oxide film 2 on the regions where the drain region 3 and the source region 4 are to be formed is partially removed, and the drain region 3 and the source region 4 are formed by diffusion. Subsequently, a polysilicon film 5 is formed on the entire surface on the main surface side of the substrate 1. This polysilicon film 5
It can be easily formed by a CVD method or the like, and the resistance can be arbitrarily adjusted by doping impurities at a high concentration during the formation.

Next, the polysilicon film 5 is patterned into a predetermined shape to form a drain electrode 5b, a source electrode 5c,
a, a silicon oxide film (SiO ₂ ) 6 is formed on the entire surface on the main surface side of the substrate 1, and the silicon oxide film 6 is further formed.
A silicon nitride film (Si ₃ N ₄ ) 7 is formed thereon. Then, the silicon nitride film 7 and the silicon oxide film 6 on a portion to be a contact portion with each of the wirings 5a are removed to expose a part of the surface of the wiring 5a. To form an aluminum film 8 and pattern the aluminum film 8 into a predetermined shape (at this time,
The wiring 8a and the pad 18 are also formed). Subsequently, on the main surface side of the substrate 1, a temperature detecting section 41 made of platinum and a heater 5
1 and the temperature detecting portions 52 and 53 are formed, a silicon oxide film (SiO ₂ ) 9 is formed on the entire surface on the main surface side of the substrate 1, and then the silicon oxide film 9 in a predetermined region is removed. A silver / silver chloride electrode 10 is formed on the main surface side. Subsequently, a platinum electrode 11 made of platinum is formed.

Thus, in this embodiment, the hypochlorite ion sensor 20, the pH sensor 30, the temperature sensor 40, the flow sensor 50, the signal processing circuit (this signal processing circuit
This is a circuit that corrects and outputs the output signal of the hypochlorite ion sensor 20 in accordance with the output signals of the H sensor 30, the temperature sensor 40, and the flow rate sensor 50). It is possible to improve the detection accuracy of hypochlorite ions while reducing the size and reducing the size of the system.

(Embodiment 2) The basic structure of an integrated ion sensor according to the present embodiment is substantially the same as that of Embodiment 1, and FIG.
As shown in (1), the signal processing circuit 12 is further integrated on the substrate 1 on which the hypochlorite ion sensor 20, the pH sensor 30, the temperature sensor 40, and the flow rate sensor 50 are integrated. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Here, the signal processing circuit 12 corrects the output signal of the hypochlorite ion sensor 20 in accordance with the output signals of the pH sensor 30, the temperature sensor 40, and the flow rate sensor 30, and adjusts the pH of the measurement liquid, This is a circuit that outputs an output signal corresponding to the accurate hypochlorite ion concentration regardless of the temperature and the flow rate.

In this embodiment, however, the pH sensor 3
In configuring a system that corrects the output signal of the hypochlorite ion sensor 2 according to the output signals of the temperature sensor 40 and the flow sensor 30, the size of the system can be further reduced.

(Embodiment 3) The basic configuration of the integrated ion sensor of this embodiment is substantially the same as that of Embodiment 1, and FIG.
As shown in FIG. 3, the silicon oxide film 2 described in the first embodiment
Is characterized in that it is composed of a LOCOS oxide film. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, however, the dielectric strength between adjacent sensors (between 20, 50, 40, 50, 30, 40) is increased, so that the influence of leak current and the like is reduced, and As a result, the detection accuracy of hypochlorite ions can be improved.

(Embodiment 4) The basic structure of an integrated ion sensor of this embodiment is substantially the same as that of Embodiment 2, and FIG.
Is characterized in that an SOI substrate is used as the substrate 1. Here, the substrate 1 has a silicon active layer 1c formed on one surface of a silicon substrate 1a via an insulating layer 1b made of a silicon oxide film.
A silicon oxide film 2 made of an S oxide film is formed to a depth reaching the insulating layer 1b. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, since the SOI substrate is used as the substrate 1, the distance between adjacent sensors (2
(Between 0 and 50, between 40 and 50, between 30 and 40), and as a result, the detection accuracy of hypochlorite ions can be improved.

(Embodiment 5) The basic configuration of an integrated ion sensor of this embodiment is substantially the same as that of Embodiment 1, and FIG.
As shown in (1), the temperature sensor 52 of the flow rate sensor 50 and the platinum electrode 11 of the hypochlorite ion sensor 20 are also used. In the present embodiment, the temperature detecting section 53 also serves as the temperature detecting section 41 of the temperature sensor 40 in the first embodiment. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the flow rate sensor 5
0 of the temperature sensor 53 according to the first embodiment.
Since the temperature detection unit 41 is also used as the temperature detection unit 41 and the temperature detection unit 52 is also used as the platinum electrode 11, the size of the substrate 1 can be reduced, and as a result, the size of the entire system can be reduced.

(Embodiment 6) The basic structure of an integrated ion sensor of this embodiment is substantially the same as that of Embodiment 2, and FIG.
As shown in (1), the feature is that the heater 51 of the flow sensor 50 is formed by diffusion resistance. Here, heater 5
As in the second embodiment, the planar shape of 1 is formed in a serpentine shape. Note that the same components as those in the second embodiment are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, the flow rate sensor 5
Since the resistivity can be made higher than that of platinum by adjusting the impurity concentration when forming the diffused resistor constituting the heater 51 of 0, the heater 51 is required to generate the same amount of heat as compared to the case of using platinum. Can be downsized, the flow sensor 50 can be downsized, and as a result, the system can be downsized.

In this embodiment, since the heater 51 of the flow sensor 50 can be formed simultaneously in the diffusion step of forming the drain region 3 and the source region 4 of the pH sensor 30, the manufacturing process can be simplified. it can.

(Embodiment 7) The basic configuration of an integrated ion sensor of this embodiment is substantially the same as that of Embodiment 2, and FIG.
As shown in (1), the heater 51 of the flow sensor 50 is formed of polysilicon. Here, similarly to the second embodiment, the planar shape of the heater 51 is formed in a serpentine shape. Note that the same components as those in the second embodiment are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, however, the flow rate sensor 5
Since the resistivity can be made higher than that of platinum by adjusting the impurity concentration during the formation of the polysilicon constituting the heater 51 of 0, the same amount of heat can be generated by heating the heater 51 as compared with the case of using platinum. Can be reduced, and the flow sensor 50 can be reduced in size.
As a result, the size of the system can be reduced.

(Embodiment 8) The basic structure of the integrated ion sensor of this embodiment is substantially the same as that of Embodiment 1, and FIG.
As shown in (1), a feature is that a recess 17 is formed on the back surface side of the portion of the substrate 1 where the heater 51 of the flow sensor 50 is formed. That is, in the present embodiment, the heater 51 is formed on the main surface side of the diaphragm 1d formed by providing the recess 17 by anisotropically etching the substrate 1 from the back side using KOH or the like. . Here, the diaphragm portion 1d is formed by forming the silicon nitride film 7 described in the first embodiment also on the back surface side of the substrate 1, patterning it into a predetermined shape, and then performing anisotropic etching from the back surface side of the substrate 1. It can be formed by performing. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the flow rate sensor 5
Since the zero heater 51 is formed on the diaphragm 1d of the substrate 1 so as to overlap with the thinner part than other parts, heat conduction becomes difficult, heat insulation is improved, and power consumption can be reduced.

(Embodiment 9) The basic configuration of an integrated ion sensor according to this embodiment is substantially the same as that of Embodiment 8, and FIG.
As shown in FIG. 0, recesses 19 b and 19 c having a depth reaching the drain region 3 and the source region 4 are formed on the back surface of the substrate 1 where the drain region 3 and the source region 4 of the pH sensor 30 are formed. , Each recess 19b, 1
It is characterized in that an aluminum film 8 ′ is formed along the inner surface of 9 c, and a portion where the aluminum film 8 ′ is not formed on the back side of the substrate 1 is covered with a silicon nitride film 7 ′. That is, in this embodiment, the drain region 3 and the source region 4 are formed in the diaphragm portions 1e and 1f formed by providing the recesses 19b and 19c by anisotropically etching the substrate 1 from the back side using KOH or the like. Are formed. Here, the diaphragm 1
d, 1e, and 1f are to form the silicon nitride film 7 described in the first embodiment also on the back side of the substrate 1, pattern it into a predetermined shape, and then perform anisotropic etching from the back side of the substrate 1. Can be formed. Note that the same components as those in the eighth embodiment are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, however, the pH sensor 3
0 is a so-called back-gate type pH sensor in which the electrode made of the aluminum film 8 'does not come into contact with the measurement liquid, so that the insulating property of the pH sensor 30 is improved and the
As a result, the detection accuracy of hypochlorite ions can be improved. Since the diaphragms 1e and 1f can be formed simultaneously with the diaphragm 1d described in the eighth embodiment, it is not necessary to add a separate manufacturing process to form the diaphragms 1e and 1f.

(Embodiment 10) The basic structure of an integrated ion sensor according to the present embodiment is substantially the same as that of the embodiment 1, and as shown in FIG. It is characterized in that the temperature detectors 52 and 53 are each formed by a polysilicon diode. Since the type and concentration of the impurity can be adjusted during the formation of polysilicon, p-type and n-type polysilicon can be formed, so that the polysilicon diode can be easily formed. In FIG. 11, 41a, 5
Reference numerals 3a and 52a denote p-type polysilicon films, respectively.
Reference numerals 1b, 53b, and 52b denote n-type silicon films. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, since each of the temperature detectors 41, 52 and 53 is formed by a polysilicon diode, each of the temperature detectors 41, 52 and 5 is formed.
As compared with the case where 3 is made of platinum, the temperature detecting sections 41, 52, 53 can be made smaller, and the substrate 1 can be made smaller, and as a result, the system can be made smaller.

(Embodiment 11) The basic structure of an integrated ion sensor according to this embodiment is substantially the same as that of Embodiment 1, and as shown in FIG.
It is characterized in that a light-shielding film 16 that shields light from the outside to the drain region 3 and the source region 4 is formed. Here, the light shielding film 16 is formed of silver and is not formed on the surface of the ion-sensitive film 7a.
Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, since the light shielding film 16 is formed on the surface of the pH sensor 30, light leakage current between the drain region 3 and the source region 4 can be reduced. The accuracy of the sensor 30 can be improved, and as a result, the detection accuracy of hypochlorite ion can be improved. Further, since the light-shielding film 16 is formed of silver, the light-shielding film 16 is formed as compared with the case where the light-shielding film 16 is formed of aluminum, polysilicon, or the like.
, The reflectance can be increased, and higher precision can be achieved. In addition, the light shielding film 16 is made of silver / silver of the hypochlorite ion sensor 20.
Since it can be formed simultaneously with the silver chloride electrode 10, there is no need to separately add a step for forming the light-shielding film 16, and it is not necessary to separately prepare an apparatus for forming the light-shielding film 16. In providing the light shielding film 16, the manufacturing process can be simplified and the manufacturing cost can be reduced.

[0048]

According to the first aspect of the present invention, at least one of a pH sensor, a temperature sensor, and a flow rate sensor is integrated on a substrate of an ion sensor for detecting a specific ion, and a system is configured. In this case, the number of components can be reduced, and the size of the system can be reduced, and the detection accuracy of the specific ion can be improved.

According to a second aspect of the present invention, in the first aspect, since the ion sensor is a hypochlorite ion sensor having a platinum electrode and a silver / silver chloride electrode, detection of hypochlorite ion is performed. There is an effect that accuracy can be improved.

According to a third aspect of the present invention, in the first or second aspect, a signal processing circuit for correcting an output signal of the ion sensor according to an output signal of the other sensor is integrated on the substrate. Therefore, there is an effect that the size of the system can be further reduced.

According to a fourth aspect of the present invention, in the first or second aspect, the substrate is a silicon substrate,
An insulating film for insulating between the sensors is provided, and the insulating film is
Since it is made of the COS oxide film, the insulation between the sensors can be enhanced, and as a result, the detection accuracy of hypochlorite ions can be further improved.

According to a fifth aspect of the present invention, in the first or second aspect of the present invention, the substrate is made of an SOI substrate, so that the insulation between the sensors can be enhanced, and as a result, hypochlorite ion There is an effect that it becomes possible to further improve the detection accuracy of.

According to a sixth aspect of the present invention, in the second aspect of the present invention, the flow rate sensor comprises a heater made of platinum and a temperature detecting portion made of platinum, and the temperature detecting portion and the platinum sensor of the hypochlorite ion sensor are used. Since the electrode is also used, the size of the system can be further reduced.

According to a seventh aspect of the present invention, in the first or second aspect of the present invention, the flow rate sensor includes a heater made of a diffusion resistor. The size of the sensor can be reduced, and as a result, the size of the system can be reduced.

According to an eighth aspect of the present invention, in the first or second aspect of the present invention, the flow rate sensor includes a heater made of polysilicon. Can be reduced,
As a result, there is an effect that the size of the system can be reduced.

According to a ninth aspect of the present invention, in the first or second aspect of the present invention, since the flow rate sensor has a recess formed on the back surface side of the substrate, the heat insulation of the flow rate sensor is improved. There is an effect that low power consumption can be achieved.

According to a tenth aspect of the present invention, in the first to ninth aspects of the present invention, the flow rate sensor and the pH sensor each have a recess formed on the back side of the substrate.
Since the pH sensor is a back-gate type pH sensor, the heat insulation of the flow sensor is improved, and the insulation of the pH sensor can be enhanced by providing an electrode of the pH sensor on the back side of the pH sensor. For higher accuracy,
In addition, the concave portion of the flow sensor and the concave portion of the pH sensor can be formed at the same time, so that the production process can be simplified.

According to an eleventh aspect of the present invention, in the first or the second aspect of the present invention, the temperature sensor includes a diode made of polysilicon as a temperature detecting portion. The temperature detector can be reduced in size, and as a result, the size of the system can be reduced.

According to a twelfth aspect of the present invention, in the second aspect of the present invention, the pH sensor has a light-shielding film made of silver on its surface. The reflectance of the light-shielding film is improved as compared with the case where the light-shielding film is made of aluminum or polysilicon, so that the light leakage current of the pH sensor can be reduced and the pH sensor can be made more precise. Since it can be formed simultaneously with the silver / silver chloride electrode of the hypochlorite ion sensor, there is no need to add a separate step for forming a light-shielding film, and an apparatus for forming a light-shielding film is separately provided. Since there is no need to prepare, there is an effect that the manufacturing process can be simplified and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment.

FIGS. 2A and 2B show the same, wherein FIG. 2A is a cross-sectional view and FIG.
3 is an enlarged view of a main part B of FIG.

FIG. 3 is a schematic configuration diagram showing a second embodiment.

FIG. 4 is a sectional view showing a third embodiment.

FIG. 5 is a sectional view showing a fourth embodiment.

FIG. 6 is a schematic configuration diagram showing a fifth embodiment.

FIG. 7 is a sectional view showing a sixth embodiment.

FIG. 8 is a sectional view showing a seventh embodiment.

FIG. 9 is a sectional view showing an eighth embodiment.

FIG. 10 is a sectional view showing a ninth embodiment.

FIG. 11 is a schematic configuration diagram showing a tenth embodiment.

FIG. 12 is a schematic configuration diagram showing an eleventh embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 10 Silver / silver chloride electrode 11 Platinum electrode 20 Hypochlorite ion sensor 30 pH sensor 40 Temperature sensor 50 Flow sensor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Jun Sakai, Matsushita Electric Works Co., Ltd., 1048 Kadoma, Kadoma, Osaka Prefecture (72) Yukio Iidaka 1048 Kadoma, Kazuma, Kadoma, Osaka, Japan Matsushita Electric Works Co., Ltd.

Claims (12)

[Claims] 1. An integrated ion sensor, wherein at least one of a pH sensor, a temperature sensor, and a flow rate sensor is integrated on a substrate of an ion sensor for detecting specific ions. 2. The integrated ion sensor according to claim 1, wherein the ion sensor is a hypochlorite ion sensor including a platinum electrode and a silver / silver chloride electrode. 3. The substrate according to claim 1, wherein a signal processing circuit for correcting an output signal of the ion sensor according to an output signal of the other sensor is integrated on the substrate. Integrated ion sensor. 4. The semiconductor device according to claim 1, wherein the substrate is a silicon substrate, and the substrate includes an insulating film that insulates the sensors from each other.
3. The integrated ion sensor according to claim 1, comprising an S oxide film. 5. The integrated ion sensor according to claim 1, wherein the substrate is formed of an SOI substrate. 6. The flow rate sensor includes a heater made of platinum and a temperature detecting section made of platinum, and the temperature detecting section is used in combination with a platinum electrode of a hypochlorite ion sensor. The integrated ion sensor according to claim 2. 7. The flow rate sensor according to claim 1, wherein the flow rate sensor includes a heater made of a diffusion resistance.
An integrated ion sensor as described in claim 1. 8. The integrated ion sensor according to claim 1, wherein the flow sensor includes a heater made of polysilicon. 9. The integrated ion sensor according to claim 1, wherein the flow rate sensor has a recess formed on a back surface side of the substrate. 10. The flow rate sensor and the pH sensor each have a recess formed on the back side of the substrate, and the pH sensor is a back gate type pH sensor. 10. The integrated ion sensor according to any one of items 9. 11. The integrated ion sensor according to claim 1, wherein the temperature sensor includes a diode made of polysilicon as a temperature detection unit. 12. The integrated ion sensor according to claim 2, wherein the pH sensor has a light-shielding film made of silver formed on a surface thereof.