JP5219906B2 - Temperature measuring apparatus, temperature measuring method, exposure apparatus, and device manufacturing method - Google Patents

Description

  The present invention relates to a temperature measuring apparatus capable of measuring temperature with high accuracy.

In a semiconductor exposure apparatus, high-precision temperature measurement at a 0.001 ° C. level is required for ultra-fine processing. For such high-precision temperature measurement, a temperature sensor using a platinum resistor is often used. In order to suppress the influence of the wiring resistance of the sensor, the temperature is detected by a 3-wire or 4-wire signal detection circuit. In many cases, a change in resistance value in a sensor is converted into a voltage signal. However, the conventional temperature measurement method has a problem that high-precision measurement cannot be performed due to an error of the temperature sensor or the signal detection circuit or a change with time of these.

  In order to further improve the measurement accuracy, Patent Document 1 compares the voltage generated when a constant current is passed through each of a plurality of reference resistors in a temperature measuring device using a three-wire resistance thermometer sensor. Thus, a temperature measuring device for obtaining the temperature is disclosed.

JP 2000-241258 A

However, when temperature correction is performed using a plurality of reference resistors as disclosed in Patent Document 1, an error in the absolute resistance value of the reference resistor and the device size become problems. The use of a plurality of higher precision reference resistors increases the cost and increases the size of the apparatus. For example, in a semiconductor exposure apparatus that requires a large number of temperature measurement apparatuses, the cost and size of the entire exposure apparatus are greatly increased.
In addition, in order to correct an error specific to the temperature sensor, it is necessary to acquire an error amount specific to the temperature sensor in advance using a temperature calibration unit or the like and perform a correction calculation at the time of actual temperature measurement. Similarly, an error inherent to the temperature detection circuit needs to be acquired in advance by a temperature calibration means or the like using a reference resistor whose value is managed with higher accuracy, and correction calculation must be performed during actual measurement. As described above, when the error inherent to the temperature sensor and the error of the temperature detection circuit are handled separately, measurement errors and calibration residuals that occur when acquiring the respective error amounts are superimposed. For this reason, the final temperature measurement error increases.
Therefore, the present invention provides a small temperature measuring apparatus with high accuracy and low cost.

  A temperature measurement device according to one aspect of the present invention is a temperature measurement device including a temperature sensor whose resistance value changes according to temperature, and temperature detection means for detecting the temperature from the resistance value of the temperature sensor. The temperature detecting means includes a reference resistor, constant current means for supplying a constant current to either the temperature sensor or the reference resistor, and the constant current to either the temperature sensor or the reference resistor. Switching means for determining whether to flow, a first potential difference generated in the temperature sensor when the constant current is passed through the temperature sensor, and the reference resistance when the constant current is passed through the reference resistor A voltage detection unit for detecting a second potential difference generated in the body, a reference potential difference of the reference resistor measured in advance, and a pre-measured synthetic offset error between the temperature sensor and the temperature detection unit. And a temperature correction means for correcting the first potential difference by adding the drift error corresponding to the difference between the second potential difference and the reference potential difference, and the combined offset error to the first potential difference. Have

  A temperature measurement method according to another aspect of the present invention measures a temperature using a temperature sensor whose resistance value changes according to temperature, and a temperature detection unit that detects the temperature from the resistance value of the temperature sensor. A method for measuring temperature, comprising a step of flowing a constant current through the temperature sensor to detect a first potential difference generated in the temperature sensor, and a flow of the constant current through a reference resistor of the temperature detecting means. Detecting a second potential difference generated in the first step, a drift error corresponding to a difference between the second potential difference and a reference potential difference of the reference resistor measured in advance, and the temperature sensor and the temperature measured in advance. And correcting the first potential difference by adding a combined offset error with the detection means to the first potential difference.

  An exposure apparatus according to another aspect of the present invention is an exposure apparatus that exposes a pattern of an original on a substrate, an illumination optical system that illuminates the original using light from a light source, and the pattern of the original A projection optical system that projects onto the substrate; and a temperature measurement device that measures a temperature inside the exposure apparatus.

  A device manufacturing method according to another aspect of the present invention includes a step of exposing a substrate using the exposure apparatus and a step of developing the exposed substrate.

  Other objects and features of the present invention are illustrated in the following examples.

  According to the present invention, it is possible to provide a small temperature measuring apparatus with high accuracy and low cost.

It is a schematic block diagram of the temperature measuring device in Example 1. It is explanatory drawing of the measurement error in the temperature measuring device of Example 1. It is a schematic block diagram of the temperature measuring device in Example 2. It is explanatory drawing of the measurement error in the temperature measuring device of Example 2. It is a schematic block diagram of the exposure apparatus in a present Example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant description is omitted.

  First, the temperature measuring apparatus according to the first embodiment of the present invention will be described. FIG. 1 is a schematic configuration diagram of a temperature measuring apparatus 100 in the present embodiment. FIG. 1A shows a state in which the constant current I is passed through the resistance temperature sensor 1, and FIG. 1B shows a state in which the constant current I is passed through the reference resistor 20a. The temperature measuring device 100 includes a resistance temperature sensor 1 (temperature sensor) whose resistance value Rt changes according to temperature, and a temperature detection circuit 8 (temperature detection) that detects the temperature from the resistance value Rt of the resistance temperature sensor 1. Means).

  The resistance thermometer sensor 1 is a four-wire temperature sensor, and is connected to the temperature detection circuit 8 using four cables 2 (first to fourth wirings 2a to 2d). The first wiring 2a and the fourth wiring 2d flow the current from the constant current source 3 (constant current means) in the temperature detection circuit 8 to the resistance thermometer sensor 1, so that both ends of the resistance thermometer sensor 1 are connected. Each is connected. The first wiring 2a and the fourth wiring 2d are wired in parallel with each other in order to suppress common-mode noise. In addition, the second wiring 2b and the third wiring 2c have a potential difference Va (first voltage) generated at both ends of the resistance thermometer sensor 1 when the current from the constant current source 3 is passed through the resistance thermometer sensor 1. In order to measure (potential difference), both ends of the resistance temperature sensor 1 are connected. The second wiring 2b and the third wiring 2c are also wired in parallel with each other in order to suppress common-mode noise.

  As shown in FIG. 1A, the potential difference Va generated at both ends of the resistance temperature sensor 1 when the constant current I flows from the constant current source 3 to the resistance temperature sensor 1 is switched via the switching means 10. Then, it is amplified by the differential amplifier section 4 (potential difference amplification means). The potential difference Va amplified by the differential amplifier unit 4 is converted from an analog signal to a digital signal by the A / D conversion unit 5. In this embodiment, the differential amplifier section 4 and the A / D converter section 5 are voltage detection means for detecting a potential difference Va generated in the resistance temperature sensor 1 when the constant current I is passed through the resistance temperature sensor 1. Configure.

  The temperature detection circuit 8 of the present embodiment is provided with a reference resistor 20a having a predetermined reference resistance value. The constant current source 3 supplies a predetermined constant current I to one of the resistance temperature sensor 1 and the reference resistor 20a. The switching means 10 determines whether the constant current I flows through either the resistance temperature sensor 1 or the reference resistor 20a. The switching operation of the switching means 10 is controlled by a control unit (not shown).

  As shown in FIG. 1B, the constant current I flows through the reference resistor 20a by the switching operation of the switching means 10. The potential difference Vb (second potential difference) generated at both ends of the reference resistor 20a when the constant current I flows through the reference resistor 20a is similar to the potential difference Va of the resistance thermometer sensor 1 through the switching means 10. Amplified by the differential amplifier 4 and converted into a digital signal by the A / D converter 5.

  Thus, the potential differences Va and Vb generated at both ends of the resistance temperature sensor 1 or the reference resistor 20a by flowing the constant current I from the constant current source 3 are detected by the differential amplifier section 4 having a high input impedance. The When the input impedance of the differential amplifier section 4 is sufficiently high, the wiring resistance to the object to be measured including the switching means 10 can be ignored. The resistance value Rt of the resistance temperature sensor 1 is obtained from the constant current I and the detected potential difference Va.

  The calculation unit 6 includes a temperature conversion unit and a temperature correction unit. The calculation unit 6 corrects each of the potential differences Va and Vb and converts them into temperature values. As will be described later, the temperature measuring apparatus 100 of the present embodiment can effectively correct errors that occur in a narrow temperature range. Hereinafter, with reference to FIG. 2, a measurement error that occurs in a narrow temperature range in the temperature measurement apparatus 100 will be described. FIG. 2A shows the relationship between the temperature and the detection signal (detection potential difference) when the measurement error Δt includes both an offset error (measurement error 21a) and a detection gain error (measurement error 21b). FIG. 2B shows the relationship between the temperature and the detection signal when only the detection gain error (measurement error 21b) after the offset error is removed occurs.

  In order to perform ultra-fine processing in a semiconductor exposure apparatus, it is necessary to manage the temperature of the environment in the exposure apparatus at a 0.01 ° C. level in a relatively narrow temperature range near room temperature. High-accuracy temperature measurement is required. The control target temperature of the environment in the exposure apparatus is a temperature near the set temperature of the temperature controlled clean room, and the accuracy at the 0.01 ° C level is required near the control target temperature of the environment in the exposure apparatus. In a limited temperature range of less than ± 1 ° C. Assuming that the first temperature range 22a (temperature range targeted by the reference resistor 20a) requiring such accuracy is T1 ± 1 ° C., in the measurement of a narrow temperature range of ± 1 ° C., the resistance temperature detector The resistance value Rt of the body sensor 1 can be regarded as a linear function of temperature.

  Here, the true temperature (true value) to be measured is t, the temperature measurement error is Δt, the resistance value of the resistance temperature sensor 1 is R (t), and the resistance value R (t of the resistance temperature sensor 1 is ) Is ΔR, the constant current value from the constant current source 3 is Io, and the current error of the constant current source 3 is ΔIo. The detection gain is G, the detection gain error is ΔG, the detection offset is O, and the detection offset error is ΔO. At this time, the measured temperature of the temperature measuring device 100 shown in FIG. 1A is expressed by the following equation (1). The detection gain G, the detection gain error ΔG, the detection offset O, and the detection offset error ΔO are the combined amounts of the resistance temperature sensor 1 and the temperature detection circuit 8.

When the expression (1) is expanded and arranged, an approximate expression represented by the following expression (2) is obtained.

From the equation (2), the true temperature t to be measured and the temperature measurement error Δt can be separated into the following equations (3) and (4), respectively.

Further, the differentiation between R (t) and Δt is expressed by the following equations (5) and (6), respectively.

From the equations (5) and (6), the following equation (7) is obtained.

Here, the detection gain error ΔG and the constant current source current error ΔIo mainly depend on resistance errors (detection gain resistance error E _G , constant current source resistance error E _I ) constituting the respective circuits. Therefore, the detection gain error ΔG and the constant current source current error ΔI _O are respectively ΔG = G · E _G and ΔIo = Io · E _I.
The above formula (7) is expressed as the following formula (8).

That is, the measurement error Δt / dt per unit temperature, which is the measurement error 21b (gain component), is the detection gain resistance error E _G (detection gain resistance accuracy) and the constant current source resistance accuracy E _I (constant current source resistance accuracy). ).

  The measurement error 21b (gain component) can be suppressed to ± 0.001 ° C./° C. by using a generally available high-precision resistor as the detection gain resistor and the resistance of the constant current source. High-precision resistors with a time stability of several ppm / year and a temperature coefficient of several ppm / ° C. are generally available (4 ppm and converted to a temperature of about 0.001 ° C.). A stable temperature detection circuit can be realized. The detection gain resistance value is preferably set to a value according to the theoretical temperature coefficient of the resistance temperature sensor 1 at the center value T1 of the first temperature detection range.

  On the other hand, the measurement error 21a (offset component) can be removed in advance before actual measurement using, for example, a temperature calibration unit (not shown). The temperature calibration is executed by combining the resistance temperature sensor 1 and the temperature detection circuit 8. Next, the measurement error after correction of the measurement error 21a (offset component) will be described with reference to FIG.

  The temperature calibration means selects a temperature near the center value T1 of the first temperature range as the first temperature range calibration point temperature Tα, and performs temperature calibration at the first temperature range calibration point temperature Tα. The measurement error 21 a (offset component) at the first temperature range calibration point temperature Tα of the measurement error Δt corresponds to a combined offset error between the resistance temperature sensor 1 and the temperature detection circuit 8. The temperature calibration means can acquire the composite offset error by measuring the potential difference Vα generated in the resistance temperature sensor 1 at the first temperature range calibration point temperature Tα and performing temperature calibration. The combined offset error acquired in advance by the temperature calibration unit is held in the correction value holding unit 7 (holding unit) of the temperature detection circuit 8.

  The calculation unit 6 of the temperature detection circuit 8 corrects the potential difference Vt detected at the temperature t (true value) to be measured using the combined offset error held in the correction value holding unit 7, thereby obtaining Tα ± 1 ° C. Highly accurate temperature detection is possible in a narrow temperature range. Note that the measurement error 21a (offset component) is a combined amount caused by the respective intrinsic components of the resistance temperature sensor 1 and the temperature detection circuit 8, and is therefore managed as a set during temperature calibration. Is preferred. Further, in this embodiment, the temperature calibration is performed using an ultra-high accuracy reference resistor having a sufficiently small measurement error 21a (offset component), thereby separating the intrinsic components of the resistance temperature sensor 1 and the temperature detection circuit 8. You may manage it.

  As described above, the high-precision resistor used as the reference resistor 20a is generally available as described above, which is stable over time and at ambient temperature, and detects and corrects drift errors in the temperature detection circuit 8. Is effective. The reference resistor 20a has an arbitrary resistance value that can be detected by the temperature detection circuit 8. However, in order to reduce the influence of non-linear errors in the temperature detection circuit 8, it is more preferable that the temperature is set in the vicinity of the resistance value corresponding to the first temperature range calibration point temperature Tα. At the time of temperature calibration at the first temperature range calibration point temperature Tα, the measurement value (reference potential difference) of the reference resistor 20a can be acquired. The temperature measuring device 100 holds the reference potential difference of the reference resistor 20a measured in advance in the correction value holding unit 7 as an initial value. The calculation unit 6 of the temperature detection circuit 8 calculates a drift error corresponding to the difference between the latest measured value (potential difference Vb) of the reference resistor 20a and the reference potential difference that is the initial value, and suppresses this drift error. The measurement error is corrected as follows.

  Specifically, the temperature correction unit (temperature correction unit) of the calculation unit 6 corrects the potential difference Va by adding the drift error and the combined offset error to the potential difference Va (first potential difference) of the resistance temperature sensor 1. To do.

  The drift error in the measurement error changes gradually with time. For this reason, at the time of temperature measurement, it is more preferable to detect the second potential difference of the reference resistor 20a and update the correction value intermittently with respect to the detection of the first potential difference of the resistance temperature sensor 1. preferable. When detecting the potential difference Vb (second potential difference) of the reference resistor 20a, the temperature detection circuit 8 cannot output the current temperature detection value. Therefore, the temperature detection circuit 8 has a storage unit (not shown), and this storage unit holds the previous temperature detection value. For this reason, when detecting the potential difference Vb of the reference resistor 20a, by outputting the previous (last) temperature detection value held in the storage unit as the current temperature detection value, the continuous temperature detection value Can be output. The temperature detection circuit 8 is preferably installed in a space adjusted to a constant temperature and a constant humidity in order to reduce the influence of environmental fluctuations such as temperature and humidity.

  Also, temperature calibration is performed at two temperatures within a relatively narrow temperature range where accuracy is required, and both a combined offset error and a combined detection gain error between the resistance temperature sensor 1 and the temperature detection circuit 8 are obtained. The measurement value may be corrected by holding it in the correction value holding unit 7. In this case, the measurement error 21b (gain component) can also be corrected, and the temperature can be detected with higher accuracy in the above temperature range. It is also possible to reduce the accuracy of the detection gain resistor and reduce the component cost while maintaining the temperature detection accuracy.

  The temperature measurement apparatus 100 of the present embodiment may further include a temperature control calculation unit that performs temperature control using the temperature detection value output from the temperature detection circuit 8, and a temperature adjustment unit that adjusts the temperature. .

  Next, a temperature measuring apparatus according to the second embodiment of the present invention will be described. FIG. 3 is a schematic configuration diagram of the temperature measuring device 100a in the present embodiment. FIG. 4 is an explanatory diagram of the measurement error after correcting the offset component. In addition to the reference resistor 20a, the temperature measuring device 100a includes a reference resistor 20b (second reference resistor) that targets a temperature range different from the temperature range that the reference resistor 20a targets. This is different from the temperature measuring apparatus 100 of the first embodiment. Further, the switching means 10a determines whether the constant current I is caused to flow through either the resistance temperature sensor 1 or the reference resistors 20a and 20b based on a command from a control unit (not shown).

  When the temperature to be measured deviates from the first temperature range 22a centered on the center value T1 and reaches the second temperature range 22b centered on the center value T2, the temperature measuring device 100a is configured to be in the second temperature range 22b. Is corrected in the same manner as in the first temperature range 22a. That is, the voltage detection unit detects a potential difference (third potential difference) generated in the reference resistor 20b when a constant current is passed through the reference resistor 20b. In addition, the calculation unit 6 serving as a temperature correction unit adds a second drift error corresponding to the difference between the third potential difference and the reference potential difference of the reference resistor 20b to the potential difference Va (first potential difference), thereby adding the potential difference Va. Correct. Therefore, according to the present embodiment, temperature detection with higher accuracy is possible.

  In the same manner as in the case of the first temperature range calibration point temperature Tα of the first temperature range 22a, a temperature near the second temperature range center value T2 is selected as the second temperature range calibration point temperature Tβ. Temperature calibration is performed on the detection value Vβ of the resistance temperature sensor 1 at the second temperature range calibration point temperature Tβ, and the resistance temperature sensor 1 and the temperature at the second temperature range calibration point temperature Tβ of the measurement error Δt. The composite offset error of the detection circuit 8a is acquired. The combined offset error acquired in advance using the temperature calibration means is held in the correction value holding unit 7. The calculation unit 6 can detect the temperature t (true value) to be measured using the combined offset error to detect the temperature with high accuracy even in the second temperature range 22b.

  When the temperature measuring device 100a performs temperature measurement in the second temperature range 22b, a reference resistor 20b (second reference) conforming to the second temperature range 22b is used as a reference resistor used for drift correction. Resistor) is used. By using such a reference resistor 20b, it is possible to reduce the influence of the nonlinear error of the temperature detection circuit 8a. A measured value (reference potential difference) of the reference resistor 20b is acquired at the time of temperature calibration at the second temperature range calibration point temperature Tβ, and this reference potential difference is held in the correction value holding unit 7 as an initial value. When the temperature measuring device 100a performs the thermometer side of the second temperature range 22b, a value obtained by calculating the difference between the latest measured value (potential difference) of the reference resistor 20b and the initial value (reference potential difference) is obtained. Used as a correction value. For this reason, the drift error in the measurement error can be effectively suppressed.

  In each of the above embodiments, when the correction value is managed by the combination of the resistance temperature sensor 1 and the temperature detection circuits 8 and 8a, it is necessary to replace both of them when a device failure occurs. However, by comparing and correcting the errors of the temperature detection circuits 8 and 8a using the high-precision reference resistors 20a and 20b, it is possible to replace the temperature detection circuits 8 and 8a alone while suppressing the errors. Specifically, first, a reference resistor external to the temperature detection circuit is connected instead of the resistance temperature sensor 1 in advance on the temperature detection board of the replacement source. A value detected by the reference resistor is stored in a storage unit (not shown) as Ref1. Similarly, for the temperature detection circuit for replacement, the same reference resistor as that obtained in advance with the aforementioned replacement source board is connected. Then, the value detected by this reference resistor is stored in the storage unit as Ref2. Here, the difference between the detection values Ref1 and Ref2 is an individual difference in error of each temperature detection circuit. After the temperature detection circuit is replaced, the individual difference is corrected by the calculation unit 6 so that the temperature detection circuit alone can be replaced.

  When calculating the individual difference of each temperature detection circuit error, it is preferable to acquire and correct the aforementioned drift error component. Further, as long as the measurement error 21a (offset component) is a sufficiently high precision reference resistor, the same individual reference resistor may not be used to obtain the correction value for the temperature detection circuit individual difference.

  By using the above temperature measuring device, it is possible to measure the temperature at the 0.001 ° C. level with high accuracy and low cost. Further, in a semiconductor exposure apparatus equipped with such a temperature measuring device, high-precision temperature control and temperature management can be performed at low cost, and the accuracy of the device can be improved.

  FIG. 5 is a schematic block diagram of a semiconductor exposure apparatus to which the temperature measuring apparatus of each of the embodiments is applied. The exposure apparatus 200 is an exposure apparatus that exposes a pattern of an original (reticle) on a substrate (on a wafer). The temperature measuring apparatuses 100 and 100a measure the temperature inside the exposure apparatus 200. As shown in FIG. 5, an exposure apparatus 200 includes an illumination apparatus 30 that irradiates exposure light, a reticle stage 31 that holds and relatively moves a reticle (original), a projection optical system 32, and a wafer (substrate). A wafer stage 33 that holds and relatively moves is provided. The exposure apparatus 200 projects and exposes a circuit pattern image formed on a reticle onto a wafer. Further, as the projection exposure method of the exposure apparatus 200, a step-and-repeat method or a step-and-scan method can be applied.

  The illumination device 30 illuminates a reticle on which a circuit pattern is formed, and includes a light source unit and an illumination optical system. The light source unit uses, for example, a laser as a light source. As the laser, an ArF excimer laser with a wavelength of about 193 nm, a KrF excimer laser with a wavelength of about 248 nm, an F2 excimer laser with a wavelength of about 153 nm, or the like can be used. The type of laser is not limited to the excimer laser, and for example, a YAG laser may be used. Further, the number of lasers is not limited.

  When a laser is used as the light source, it is preferable to use a light beam shaping optical system that shapes the parallel light beam from the laser light source into a desired beam shape and an incoherent optical system that makes the coherent laser light beam incoherent. The light source that can be used for the light source unit is not limited to a laser, and one or a plurality of lamps such as a mercury lamp and a xenon lamp can be used. The illumination optical system is an optical system that illuminates a reticle using light from a light source, and includes a lens, a mirror, a light integrator, a diaphragm, and the like.

  The projection optical system 32 is an optical system that projects a reticle pattern onto a wafer. The projection optical system 32 is configured by an optical system including only a plurality of lens elements, or an optical system (catadioptric optical system) having a plurality of lens elements and at least one concave mirror. An optical system having a plurality of lens elements and at least one diffractive optical element such as a kinoform, or an all-mirror optical system can also be used. The exposure apparatus 200 can be used for manufacturing a semiconductor device such as a semiconductor integrated circuit or a device on which a fine pattern such as a micromachine or a thin film magnetic head is formed.

  A device (semiconductor integrated circuit element, liquid crystal display element, etc.) includes a step of exposing a substrate (wafer, glass plate, etc.) coated with a photosensitive agent using the exposure apparatus of any one of the embodiments described above, and the substrate It is manufactured by undergoing a development step and other known steps.

  According to each of the embodiments, it is possible to provide a low-cost and high-accuracy temperature measurement device and temperature measurement method. Further, it is possible to provide an exposure apparatus and a device manufacturing method capable of manufacturing a high-quality device.

  The embodiment of the present invention has been specifically described above. However, the present invention is not limited to the matters described as the above-described embodiments, and can be appropriately changed without departing from the technical idea of the present invention.

1: RTD sensor 3: Constant current source 4: Differential amplifier unit 5: A / D conversion unit 6: Calculation unit 7: Correction value holding unit 8: Temperature detection circuit I: Constant current Va, Vb: Potential difference Rt : Resistance value 10: Switching means 20a, 20b: Reference resistor

Claims (6)

A temperature measurement device comprising a temperature sensor whose resistance value changes according to temperature, and a temperature detection means for detecting the temperature from the resistance value of the temperature sensor,
The temperature detecting means includes
A reference resistor;
Constant current means for supplying a constant current to either the temperature sensor or the reference resistor;
Switching means for determining whether to pass the constant current to the temperature sensor or the reference resistor;
A first potential difference generated in the temperature sensor is detected when the constant current is passed through the temperature sensor, and a second potential difference generated in the reference resistor is detected when the constant current is passed through the reference resistor. Voltage detecting means for
Holding means for holding a reference potential difference of the reference resistor measured in advance, and a combined offset error between the temperature sensor and the temperature detecting means measured in advance;
Temperature correction means for correcting the first potential difference by adding the drift error corresponding to the difference between the second potential difference and the reference potential difference and the combined offset error to the first potential difference. A temperature measuring device characterized by that. The temperature detecting means further includes a second reference resistor that targets a temperature range different from a temperature range that the reference resistor targets.
The voltage detecting means detects a third potential difference generated in the second reference resistor when the constant current is passed through the second reference resistor;
The temperature correction means corrects the first potential difference by adding a second drift error corresponding to a difference between the third potential difference and a reference potential difference of the second reference resistor to the first potential difference. The temperature measuring device according to claim 1, wherein: The voltage detecting means intermittently detects the second potential difference with respect to the detection of the first potential difference;
The temperature correction means outputs a temperature detection value obtained by correcting the first potential difference acquired last when the second potential difference of the reference resistor is detected. The temperature measuring device according to claim 1. A temperature measurement method for measuring temperature using a temperature sensor whose resistance value changes according to temperature and a temperature detection means for detecting the temperature from the resistance value of the temperature sensor,
Detecting a first potential difference generated in the temperature sensor by passing a constant current through the temperature sensor;
Passing a constant current through a reference resistor of the temperature detecting means to detect a second potential difference generated in the reference resistor;
A drift error corresponding to a difference between the second potential difference and a reference potential difference of the reference resistor measured in advance, and a combined offset error between the temperature sensor and the temperature detection unit measured in advance are calculated as the first offset. And correcting the first potential difference by adding to the potential difference. An exposure apparatus that exposes a pattern of an original on a substrate,
An illumination optical system that illuminates the original using light from a light source;
A projection optical system that projects the pattern of the original onto the substrate;
An exposure apparatus comprising: the temperature measurement apparatus according to claim 1, which measures a temperature inside the exposure apparatus. Exposing the substrate using the exposure apparatus according to claim 5;
And developing the exposed substrate. A device manufacturing method comprising: