JP2012159323A - Thermal infrared detection method and thermal infrared detection device - Google Patents

Abstract

A thermal sensor using a Schottky barrier diode is used to remove an error caused by photoelectric conversion when measuring a temperature change by detecting infrared rays, thereby obtaining a more accurate measurement value.
A metal thin film and an SOI layer form a Schottky barrier diode (hereinafter referred to as a diode). The thermal sensor is configured using a diode 1. The control means 6 opens the shutter 22 and the current value A flowing through the reverse-biased diode 1 in a state where the light from the infrared generation source 20 does not hit the diode 1, and the light from the infrared generation source 20 hits the diode 1. In the state, the current value B flowing through the reverse-biased diode 1 and the current value C flowing through the diode 1 when the diode 1 is in a state of being lighted are measured by the ammeter 5. Let And the calculation means 9 calculates (current value B-current value C) -current value A etc., and estimates the temperature change of a thermal type sensor.
[Selection] Figure 2

Description

  The present invention relates to a thermal infrared detection method and a thermal infrared detection apparatus, and more particularly, to a thermal infrared detection method and thermal which detect infrared including a wavelength region where photoelectric conversion occurs with a thermal sensor using a Schottky barrier diode. Type infrared detector.

  A Schottky barrier diode is an element in which metal is brought into contact with the surface of silicon, a Schottky barrier is formed at the interface between silicon and metal, and diode characteristics are exhibited by the barrier. The Schottky barrier varies depending on the type of metal in contact with silicon, but is generally smaller than the band gap of silicon. The band gap of silicon is about 1.1 eV. For example, when n-type silicon is brought into contact with Mo (molybdenum), a Schottky barrier of about 0.67 V can be formed. When light enters the interface portion of this Schottky barrier, it functions as a normal photodiode, and photons up to a wavelength of about 1.8 μm are converted into electron hole pairs by photoelectric conversion to become current. Since visible light has a wavelength of up to about 0.8 μm, the Schottky barrier diode functions as a photoelectric conversion sensor that detects infrared rays.

  On the other hand, when the Schottky barrier diode is reverse-biased, its resistance change (which is equal to the current value change when the bias voltage is constant) is very sensitive to temperature, and the resistance value with a slight temperature change Is known to change significantly. Therefore, the Schottky barrier diode when reverse-biased can measure the temperature from its resistance value, which is called a thermistor. If the temperature change is caused by absorption of infrared rays, it means that infrared rays are being measured. This is an infrared thermal sensor because it measures infrared light once converted to heat.

  Thus, it can be seen that the Schottky barrier diode can be used both as a photoelectric conversion sensor and a thermal sensor for infrared rays. For example, Patent Document 1 describes a method of taking out and utilizing both photoelectric conversion type and thermal type signals. In the sensor described in Patent Document 1, infrared rays having different wavelengths are detected by the photoelectric conversion type and the thermal type.

JP-A-10-79499

  Conventionally, when a Schottky barrier provided on a silicon substrate is used as a thermal Schottky barrier thermistor, it is basically used at a wavelength different from the wavelength at which photoelectric conversion occurs as described in Patent Document 1. . Usually, a bandpass filter is used to select a target wavelength and detect only that wavelength.

  However, a problem arises when it is desired to measure the wavelength region including the wavelength at which photoelectric conversion occurs with a thermal type. In the case of the thermal type, the current value is detected by applying a reverse bias, and the change is observed. However, the current generated by photoelectric conversion is mixed in the current, and an accurate change in the current value can be measured. Disappear.

  The present invention has been made in view of the above points, and when a thermal sensor using a Schottky barrier diode is used to detect an infrared ray to measure a temperature change, an error caused by photoelectric conversion can be removed. It is an object of the present invention to provide a thermal infrared detection method and a thermal infrared detection device capable of obtaining a more accurate measurement value.

  In order to achieve the above object, a thermal infrared detection method according to a first aspect of the present invention is such that infrared rays from an infrared source do not enter a Schottky barrier diode and a reverse bias voltage is applied to the Schottky barrier diode. A first current value measuring step for measuring the current value A of the Schottky barrier diode in a state of applying an infrared ray, an infrared ray from an infrared source is incident on the Schottky barrier diode, and A second current value measuring step for measuring the current value B of the Schottky barrier diode with the reverse bias voltage applied to the barrier diode, and the infrared ray from the infrared source is incident on the Schottky barrier diode And the current value of the Schottky barrier diode with the Schottky barrier diode short-circuited. Is calculated based on the third current value measuring step for measuring the current value, the difference value obtained by subtracting the current value C from the current value B, and the current value A, and the temperature of the thermal sensor using the Schottky barrier diode is calculated. And a calculation step for estimating the change.

  In order to achieve the above object, the thermal infrared detection method of the second invention is the forward direction of the Schottky barrier diode in the state where the infrared rays from the infrared generation source are not incident on the Schottky barrier diode. In the forward characteristic measurement step for measuring the characteristics, the infrared light from the infrared source is not incident on the Schottky barrier diode and a reverse bias voltage is applied to the Schottky barrier diode. A first current value measuring step for measuring a current value A of the barrier diode, and an infrared ray from an infrared source is incident on the Schottky barrier diode and a reverse bias voltage is applied to the Schottky barrier diode; In this state, a second current value measuring step for measuring the current value B of the Schottky barrier diode, Estimated from the open-circuit voltage measurement step for measuring the open-circuit voltage of the Schottky barrier diode and the open-circuit voltage measured in the open-circuit voltage measurement step with the infrared rays from the external line source incident on the Schottky barrier diode Calculation is performed based on the third current value measurement step for measuring the photoelectric effect current as the current value C ′, the difference value obtained by subtracting the current value C ′ from the current value B, and the current value A, and the Schottky barrier And a calculation step for estimating a temperature change of the thermal sensor using the diode.

  In order to achieve the above object, a thermal infrared detector according to a third aspect of the present invention includes a thermal sensor having a Schottky barrier diode, and infrared rays from an external infrared generation source. Light control means for irradiating or blocking the light source, a voltage source for applying a bias voltage to the Schottky barrier diode, an ammeter for measuring a current flowing through the Schottky barrier diode, and a Schottky barrier diode On the other hand, the current value A of the Schottky barrier diode in a state where the light irradiation control means is controlled so that the infrared light from the infrared light source is not incident and the reverse bias voltage is applied from the voltage source, and the light irradiation The Schottky buffer in a state where the infrared ray from the infrared ray generation source is incident by controlling the control means and the reverse bias voltage is applied from the voltage source. A current value B of the diode, and a current value C of the Schottky barrier diode when the infrared ray from the infrared source is incident and the Schottky barrier diode is short-circuited, respectively. A current value measurement control unit that measures and stores the current value, and a current value A that is obtained by subtracting the current value C from the current value B that is measured and stored by the current value measurement unit And a calculating means for estimating the temperature change of.

  In order to achieve the above object, a thermal-type infrared detection device according to a fourth aspect of the present invention includes a thermal-type sensor having a Schottky barrier diode, and infrared rays from an external infrared generation source. Light control means for irradiating or blocking the light source, a voltage source for applying a bias voltage to the Schottky barrier diode, an ammeter for measuring a current flowing through the Schottky barrier diode, a voltage source and a Schottky barrier The switch means for connecting or blocking the path between the diode and the light irradiation control means to control the irradiation of the Schottky barrier diode in a state where the infrared ray from the infrared source is not incident on the Schottky barrier diode. Forward characteristic measurement means for measuring and storing the forward characteristic, and infrared from the infrared source by controlling the light irradiation control means Is not incident on the Schottky barrier diode and the reverse bias voltage is applied to the Schottky barrier diode from the voltage source and the light irradiation control means The current value of the Schottky barrier diode when the infrared ray from the infrared source is controlled to enter the Schottky barrier diode and the reverse bias voltage is applied to the Schottky barrier diode from the voltage source. A current source measurement control means for measuring B with an ammeter, and a light source control means for controlling the switch means in a state where the infrared ray from the infrared ray generation source is incident on the Schottky barrier diode, and the voltage source The open circuit voltage of the Schottky barrier diode by blocking the path between the Schottky barrier diode and the Schottky barrier diode. An open-circuit voltage measurement control means that stores and stores the photoelectric effect current estimated based on the forward characteristics measured by the forward-direction characteristic measurement means from the open-circuit voltage measured by the open-circuit voltage measurement control means as the current value C ′. A photoelectric effect current estimating means for storing; and a calculating means for performing a calculation based on a difference value obtained by subtracting the current value C ′ from the current value B and the current value A to estimate a temperature change of the thermal sensor. Features.

  According to the present invention, when measuring a temperature change by detecting infrared rays with a thermal sensor using a Schottky barrier diode, an error caused by photoelectric conversion can be removed, and a more accurate measurement value can be obtained. .

It is a block diagram of one embodiment of a thermal sensor used in the thermal infrared detector of the present invention. It is a block diagram of 1st Embodiment of the thermal type infrared rays detection apparatus of this invention. It is a flowchart of 1st Embodiment of the thermal infrared detection method of this invention. It is a figure which shows each electric current value in the state which has hit the Schottky barrier diode which applied reverse bias, and the state which is not hitting light. FIG. 5 is a characteristic diagram showing a difference between two current values shown in FIG. 4. It is a figure which shows the change rate of the electric current when not correct | amending, and the change rate of the electric current when correct | amending. It is a block diagram of 1st Embodiment of the thermal type infrared rays detection apparatus of this invention. It is a flowchart of 2nd Embodiment of the thermal type infrared detection method of this invention. It is a figure which shows the diode characteristic of the forward direction of the Schottky barrier diode measured in the state which does not shine.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an overall configuration diagram of an embodiment of a thermal sensor used in a thermal infrared detector according to the present invention. In the figure, a thermal sensor 100 is made using an SOI substrate. A silicon oxide film 102 is provided on the support substrate 108, and a thin silicon layer (SOI layer) 104 is provided thereon. The SOI layer 104 is etched to leave only the sensor portion, and a cavity 101 is formed thereunder. That is, the SOI layer 104 has a structure floating in the air.

  A metal thin film 105 (for example, molybdenum (Mo)) is formed on the etched SOI layer 104, and forms a Schottky barrier with the SOI layer 104. A heat absorbing material 106 (for example, a material that absorbs infrared rays such as tungsten (W)) is stacked on the metal thin film 105 to assist absorption of infrared rays.

Here, the SOI layer 104 is n-type, and has a p ⁺ impurity diffusion region serving as a guard ring of a Schottky barrier diode and an n ⁺ diffusion layer serving as a contact layer to the SOI layer 104 on the surface thereof. The wirings 103 and 107 are made of, for example, titanium (Ti), and are wirings for electrically connecting the SOI layer 104 and the metal thin film 105 from the outside. The thermal sensor 100 having this structure is also an infrared sensor using a Schottky barrier thermistor.

  Next, the operation of the thermal sensor 100 will be described.

  First, when infrared rays are absorbed by the metal thin film 105 or the heat absorbing material 106, it is changed to heat, and the SOI layer 104 is also warmed. As a result, the reverse bias current and resistance value of the Schottky barrier diode formed at the interface between the SOI layer 104 and the metal thin film 105 change. From the change in resistance value, the temperature change of the SOI layer 104, the metal thin film 105, and the heat absorption material 106 can be known. As a result, it is possible to obtain information such as estimating the temperature of an infrared ray generation source (for example, a human body) that emits infrared rays. The heat accumulated in the SOI layer 104, the metal thin film 105, and the heat absorbing material 106 will eventually escape through the silicon oxide film 102.

(First embodiment)
FIG. 2 shows a configuration diagram of a first embodiment of a thermal infrared detector according to the present invention. 2, the thermal infrared detector 31 of the present embodiment includes the thermal sensor 100 of FIG. 1, a voltage source 4, an ammeter 5, a control unit 6, a measurement data processing unit 7, an output unit 10, and an optical filter. 21 and a shutter 22 that accurately detect infrared rays emitted from an infrared generation source (for example, a human body) 20, and calculate the temperature of the infrared generation source 20 from the temperature change of the thermal sensor 100.

  Here, in FIG. 2, the thermal sensor 100 in FIG. 1 schematically depicts only the SOI layer 3 (corresponding to the SOI layer 104 in FIG. 1) and the metal thin film 2 (corresponding to the metal thin film 105 in FIG. 1). is there. The metal thin film 2 and the SOI layer 3 form a Schottky barrier diode 1. The Schottky barrier diode 1 corresponds to the thermal sensor 100 shown in FIG.

  The voltage source 4 applies a reverse bias voltage to the Schottky barrier diode 1. The ammeter 5 is connected between the SOI layer 3 and the negative terminal of the voltage source 4 and measures the current flowing through the Schottky barrier diode 1. The control means 6 is, for example, measurement software for a personal computer (personal computer). The measurement data processing means 7 includes a memory 8 and a calculation means 9. The measurement data processing means 7 records the current value measured by the ammeter 5 in the memory 8, and the calculation means 9 performs calculation described later based on the current value recorded in the memory 8. Processing is performed to calculate changes in current. The output means 10 comprises a monitor, for example, and outputs the calculation result calculated by the calculation means 9. The control means 6 and the memory 8 constitute current value measurement control means of the third invention.

  The infrared generation source 20 is, for example, a 2000 degree filament lamp, and emits light including infrared rays in a wavelength region where photoelectric conversion occurs at the interface of the Schottky barrier diode 1. The optical filter 21 cuts visible light out of the light emitted from the infrared light generation source 20 and transmits the infrared light. The shutter 22 turns on and off the infrared light transmitted through the optical filter 21. The control means 6 controls the bias value of the voltage source 4, the measurement timing of the ammeter 5, the processing method of the measurement data processing means 7, and the on / off of the shutter 22. Although the shutter 22 is used here, the power source of the infrared ray generation source 20 may be turned on and off.

  Next, operations by the control means 6 and the measurement data processing means 7 will be described with reference to the flowchart of FIG.

  First, the control means 6 closes (turns off) the shutter 22 and flows from the infrared ray generation source 20 to the Schottky barrier diode 1 that is reverse-biased in a state where the light does not strike the Schottky barrier diode 1. The ammeter 5 is caused to measure the current value A (step S1). This current value A is stored in the memory 8.

  Subsequently, the control means 6 opens (turns on) the shutter 22 and applies the reverse-biased Schottky barrier diode 1 in a state where the light from the infrared source 20 strikes the Schottky barrier diode 1. The ammeter 5 is caused to measure the flowing current value B (step S2). This current value B is stored in the memory 8. Here, when the infrared rays reach the interface portion between the metal thin film 2 and the SOI layer 3 of the Schottky barrier diode 1, photoelectric conversion occurs, and when the metal thin film 2 is molybdenum, the wavelength is 1.1 to 1.8 μm. About 3 to 5% of the light in the range is an electron hole pair, which is included in the reverse bias current value B. As a result, the resistance is apparently reduced, and it is erroneously measured that the temperature change is occurring more than actual. Although it is possible to reduce it by optical devices so that light does not reach the interface between the metal thin film 2 and the SOI layer 3 of the Schottky barrier diode 1, it is difficult to make it zero.

  Therefore, in order to correct this, in the present embodiment, the control means 6 opens the shutter 22, and the bias voltage is set to 0 V while the light from the infrared ray generation source 20 strikes the Schottky barrier diode 1. (Or a short circuit without a power source), the current value C flowing through the Schottky barrier diode 1 at that time is measured by the ammeter 5 (step S3). This current value C is equal to the current value by photoelectric conversion. The memory 8 also stores this current value C.

  Subsequently, the calculation means 9 reads the current values A, B, C stored in the memory 8 and calculates the change in current by calculating the following equation (step S4).

Change in current = current value B−current value C−current value A (1)
Since the current value C is equal to the current value by photoelectric conversion, if the current value C is subtracted from the current value B, it becomes a change in the current value due to a true temperature change. The calculating means 9 also calculates the rate of change of current by the following equation.

Current change rate = {(current value B−current value C) / current value A} −1 (2)
The calculation means 9 supplies the output means 10 with the calculation result of the current change and the current change rate and outputs the result.

  Here, in the measurement of the current value A when there is no light from the infrared ray generation source 20, the influence of the photoelectric effect is ignored. Even if there is no light from the infrared ray generation source 20, the light reaches the Schottky barrier diode 1 as background radiation. Strictly speaking, even if there is no light from the infrared ray generation source 20, the photoelectric effect exists. To do. However, light in the wavelength range of 1.1 to 1.8 μm included in the background radiation (room temperature of about 300 K) is very small and is ignored here. Of course, when this component cannot be ignored (for example, when another infrared radiation source exists and is affected by this), it is necessary to take this into consideration. Assuming that the current value due to the photoelectric effect at that time is the current value D, the current change and the current change rate are respectively calculated by the following equations.

Change in current = (current value B−current value C) − (current value A−current value D) (3)
Rate of change of current = {(current value B−current value C) / (current value A−current value D)} − 1
FIG. 4 shows the current flowing through the Schottky barrier diode 1 on the vertical axis and the reverse bias voltage on the horizontal axis. FIG. 4 shows a current value B in a state (lamp ON) in which light from the infrared ray generation source 20 is applied to the Schottky barrier diode 1 to which reverse bias is applied, when the reverse bias voltage is changed. The current value A in a state where the light is not irradiated (lamp OFF) is indicated by II. However, since it is a reverse bias voltage, the value is negative. Comparing the current values A and B, it can be seen that a larger amount of current flows in the same reverse bias voltage than the current value A in which the light is applied, compared to the current value A in which the light is not applied. Here, since Mo (molybdenum) is used as the metal thin film 2, the current is Mo current and the voltage is Mo voltage.

  FIG. 5 shows a reverse bias voltage versus current characteristic of the difference between the current value B and the current value A (current value B−current value A). Among these, the difference current value when the reverse bias is 0 V is a current value generated by photoelectric conversion, and is a current value C.

  Now, the change in temperature appears in the rate of change in current. FIG. 6 compares the rate of change when the current value C is not corrected with the rate of change when the current value C is corrected. In FIG. 6, the vertical axis represents the current change rate (%), and the horizontal axis represents the reverse bias voltage (V). In FIG. 6, III indicates the characteristic of the rate of change of current when not corrected, calculated by the following equation.

Current change rate = (current value B / current value A) −1
On the other hand, in FIG. 6, IV indicates the characteristic of the rate of change of current when corrected, calculated by the following equation.

Current change rate = {(current value B−current value C) / current value A} −1 (6)
Since the current change rate is compared with the same bias, it is equal to the reciprocal of the resistance change rate.

  As can be seen from the characteristics III and IV shown in FIG. 6, the rate of change of the current when not corrected is different depending on the reverse bias voltage value as indicated by III, and it is not known which value is correct. On the other hand, as shown by IV, the corrected current change rate is almost constant at a little over 4% when the reverse bias voltage is −0.8 V or less. Since the influence of the temperature change on the resistance value should be constant regardless of the bias value, it can be seen that the correction was correctly performed.

  The current value A may not be measured every time, but may be measured when the temperature is apparently changed or measured every predetermined time and stored in the memory 8.

(Second Embodiment)
FIG. 7 shows a configuration diagram of a second embodiment of a thermal infrared detector according to the present invention. In the figure, the same components as those in FIG. The thermal infrared detector 32 of the present embodiment includes a voltmeter 11 for measuring the voltage of the Schottky barrier diode 1 and the switch means of the present invention in the configuration of the thermal infrared detector 31 shown in FIG. A switch 12 is added. In addition to the control operation of the control means 6, the control means 13 also controls on / off of the switch 12, and transmits the current value at this time to the measurement data processing means 7. The voltmeter 11 is connected between the metal thin film 2 and the SOI film 3. The switch 12 is a switch for connecting or blocking the path between the metal thin film 2 and the positive terminal of the voltage source 4.

  The control means 13 and the memory 8 constitute current value measurement control means, open-circuit voltage measurement control means, and photoelectric effect current estimation means of the fourth invention.

  Next, the operations of the control means 13 and the measurement data processing means 7 in FIG. 7 will be described with reference to the flowchart in FIG.

  First, the control means 13 closes (turns off) the shutter 22 and flows from the infrared ray generation source 20 to the Schottky barrier diode 1 that is forward-biased in a state where the light does not strike the Schottky barrier diode 1. The current value is measured by the ammeter 5 and the forward bias voltage value is measured by the voltmeter 11, and the forward bias current-voltage characteristics (forward diode characteristics) are calculated based on these current values and voltage values. The calculation result is stored in the memory 8 (step S11).

  Subsequently, the control means 13 closes the shutter 22 and sets the current value A flowing through the reverse-biased Schottky barrier diode 1 in a state where light from the infrared source 20 does not strike the Schottky barrier diode 1. The ammeter 5 is measured (step S12). This current value A is stored in the memory 8.

  Subsequently, the control means 13 opens (turns on) the shutter 22 and applies the reverse-biased Schottky barrier diode 1 in a state where light from the infrared source 20 strikes the Schottky barrier diode 1. The ammeter 5 is caused to measure the flowing current value B (step S13). This current value B is stored in the memory 8. In steps S11 to S13, the switch 12 is closed, and the metal thin film 2 and the positive terminal of the voltage source 4 are connected.

  Subsequently, the control means 13 continues to open the shutter 22 so that the light from the infrared radiation source 20 strikes the Schottky barrier diode 1, while simultaneously opening the switch 12 to open the metal thin film 2 and the voltage source 4. And the voltage value measured by the voltmeter 11 at that time (that is, the open voltage of the Schottky barrier diode 1) is stored in the memory 8 (step S14).

  Subsequently, the calculation means 9 estimates the photoelectric effect current from the open circuit voltage read from the memory 8, measures it as a current value C ', and stores it in the memory 8 (step S15). Then, the calculation means 9 reads out the current values A, B, C ′ stored in the memory 8 and calculates the change in current by calculating the following equation, and outputs the calculation result to the output means 10 ( Step S16).

Change in current = current value B−current value C′−current value A (7)
Since the current value C ′ in the equation (7) is a photoelectric effect current value estimated from the open-circuit voltage of the Schottky barrier diode 1, if this current value C ′ is subtracted from the current value B, the current value C ′ It can be said that this is a change in current value due to the change.

  The point of this embodiment is that the method of estimating the current value C ′ by the photoelectric effect is different from that of the first embodiment. In the present embodiment, first, the forward diode characteristics of the Schottky barrier diode 1 in a state where no light is applied are measured and stored (step S11). Next, the open voltage of the Schottky barrier diode 1 is measured in a state where light is shining, that is, in a state where photoelectric conversion is occurring (step S14). In the present embodiment, when carriers generated by photoelectric conversion at the interface portion of the Schottky barrier diode 1 accumulate, a voltage is generated. When the current value is read from the forward characteristics measured at the voltage, It utilizes the property that it is equal to the current value generated by photoelectric conversion.

  For example, FIG. 9 shows the forward characteristics of the Schottky barrier diode 1 measured in a state where no light is applied (lamp OFF). When the open-circuit voltage of the Schottky barrier diode 1 was measured in a state where it was exposed to light, it was 17 mV. When the value of 17 mV was read from the measured diode characteristics shown in FIG. 9, the current value (Mo current value) of the Schottky barrier diode 1 was 11.7 nA. This value is equal to the current value measured by short-circuiting as in the first embodiment (however, the current value is reversed between positive and negative).

  When the current value generated by photoelectric conversion becomes small, it may be difficult to measure the current value. Since it is often easier to measure the voltage than the current, this embodiment is effective in such a case.

  Note that the current value A and the forward characteristic of the diode may be measured every time when it is clear that the temperature has changed or at a predetermined time and stored in the memory 8 without being measured each time. . Further, the measurement order of the current values is not limited to the order of the current values A, B, and C (or C ′) in the above embodiments. However, when the current value A is measured after measuring the current values B and C (or C ′), it is necessary to wait until the Schottky barrier diode 1 reaches the ambient temperature after a sufficient time. Further, step S14 for measuring the open-circuit voltage of the Schottky barrier diode 1 may be executed before step S13 in FIG.

DESCRIPTION OF SYMBOLS 1 Schottky barrier diode 2,105 Metal thin film 3 SOI layer 4 Voltage source 5 Ammeter 6,13 Control means 7 Measurement data processing means 8 Memory 9 Calculation means 10 Output means 11 Voltmeter 12 Switch 100 Thermal sensor 101 Cavity 102 Silicon oxide film 103, 107 Wiring 104 Silicon layer (SOI layer)
105 Metal thin film 106 Heat absorption material 108 Support substrate

Claims (4)

The current value A of the Schottky barrier diode is measured in a state where the infrared ray from the infrared source is not incident on the Schottky barrier diode and a reverse bias voltage is applied to the Schottky barrier diode. A first current value measuring step,
In the state where the infrared rays from the infrared source are incident on the Schottky barrier diode and a reverse bias voltage is applied to the Schottky barrier diode, the current value B of the Schottky barrier diode is A second current value measuring step for measuring;
Infrared light from the infrared light source is incident on the Schottky barrier diode, and the Schottky barrier diode is short-circuited to measure a current value C of the Schottky barrier diode. Current value measuring step of
A calculation step of performing a calculation based on a difference value obtained by subtracting the current value C from the current value B and the current value A, and estimating a temperature change of a thermal sensor using the Schottky barrier diode; A thermal infrared detection method comprising: A forward characteristic measuring step for measuring the forward characteristic of the Schottky barrier diode in a state where infrared rays from an infrared source are not incident on the Schottky barrier diode;
The current value A of the Schottky barrier diode is not incident on the Schottky barrier diode and the reverse bias voltage is applied to the Schottky barrier diode. A first current value measuring step for measuring
In the state where the infrared rays from the infrared source are incident on the Schottky barrier diode and a reverse bias voltage is applied to the Schottky barrier diode, the current value B of the Schottky barrier diode is A second current value measuring step for measuring;
An open circuit voltage measurement step for measuring an open circuit voltage of the Schottky barrier diode in a state where infrared light from the infrared light source is incident on the Schottky barrier diode;
A third current value measuring step of measuring the photoelectric effect current estimated from the open voltage measured in the open voltage measuring step as a current value C ′;
A calculation step of performing a calculation based on a difference value obtained by subtracting the current value C ′ from the current value B and the current value A, and estimating a temperature change of a thermal sensor using the Schottky barrier diode; A thermal infrared detection method comprising: A thermal sensor having a Schottky barrier diode;
Light control means for irradiating or blocking the Schottky barrier diode with infrared rays from an external infrared source;
A voltage source for applying a bias voltage to the Schottky barrier diode;
An ammeter for measuring the current flowing through the Schottky barrier diode;
The Schottky in a state in which the light irradiation control means is controlled to make the infrared radiation from the infrared generation source not incident on the Schottky barrier diode and a reverse bias voltage is applied from the voltage source. The current value A of the barrier diode and the Schottky barrier in a state in which infrared light from the infrared light source is incident by controlling the light irradiation control means and a reverse bias voltage is applied from the voltage source A current value B of the diode, and a current value C of the Schottky barrier diode when the infrared light from the infrared light source is incident and the Schottky barrier diode is in a short-circuit state, Current value measurement control means for measuring and storing by the ammeter;
Calculation means for performing a calculation based on a difference value obtained by subtracting the current value C from the current value B measured and stored by the current value measurement means and the current value A, and estimating a temperature change of the thermal sensor. And a thermal infrared detecting device. A thermal sensor having a Schottky barrier diode;
Light control means for irradiating or blocking the Schottky barrier diode with infrared rays from an external infrared source;
A voltage source for applying a bias voltage to the Schottky barrier diode;
An ammeter for measuring the current flowing through the Schottky barrier diode;
Switch means for connecting or blocking a path between the voltage source and the Schottky barrier diode;
Forward characteristics for measuring and storing the forward characteristics of the Schottky barrier diode in a state where the infrared light from the infrared source is not incident on the Schottky barrier diode by controlling the light irradiation control means Measuring means;
A state in which the light irradiation control means is controlled so that the infrared light from the infrared generation source is not incident on the Schottky barrier diode, and a reverse bias voltage is applied to the Schottky barrier diode from the voltage source The Schottky barrier diode current value A and the light irradiation control means are controlled so that infrared light from the infrared generation source is incident on the Schottky barrier diode and reversely applied from the voltage source. Current value measurement control means for measuring, with the ammeter, a current value B of the Schottky barrier diode in a state where a bias voltage is applied to the Schottky barrier diode;
In the state where the light irradiation control means is controlled and the infrared rays from the infrared generation source are incident on the Schottky barrier diode, the switch means is controlled to control the voltage source and the Schottky barrier diode. An open-circuit voltage measurement control means for measuring and storing the open-circuit voltage of the Schottky barrier diode by blocking the path between
Photoelectric effect current estimation means for storing a photoelectric effect current estimated based on the forward characteristic measured by the forward characteristic measurement means from the open voltage measured by the open voltage measurement control means as a current value C ′; ,
A thermal type comprising: a calculation means for performing a calculation based on a difference value obtained by subtracting the current value C ′ from the current value B and the current value A, and estimating a temperature change of the thermal type sensor. Infrared detector.

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