JP5203800B2 - Temperature measuring member, temperature measuring device and temperature measuring method - Google Patents

Description

  The present invention relates to a temperature measurement member, a temperature measurement device, and a temperature measurement method for measuring the highest temperature among thermal histories received by an object to be measured (for example, a substrate in the field of manufacturing semiconductors or liquid crystals). is there.

  Typical measuring tools for measuring the temperature of an object to be measured include those that use changes in the thermal expansion coefficient of gases and liquids, and those that measure changes in the electrical resistance of metals (platinum resistance temperature sensors). ), Measuring temperature change in semiconductor characteristics (thermistor), measuring thermoelectromotive force generated at the contact point of dissimilar alloys (thermocouple), measuring the intensity of infrared rays emitted from the object to be measured, etc. (For example, refer to Patent Document 1). In addition, a seal-type temperature measuring device using the melting point of the substance is also commercially available.

  Temperature measurement is performed in various scenes, and an appropriate temperature measurement tool is selected according to the object to be measured. In particular, thermocouples are used as precise temperature measuring instruments in many fields.

  By the way, temperature measurement is performed everywhere in the field of manufacturing semiconductors and liquid crystals. Since the substrate is mainly glass in the liquid crystal manufacturing field, heat treatment near 150 to 400 ° C., which is lower than the heat resistant temperature of glass, is frequently used. In the semiconductor manufacturing field, 150 to 600 ° C., which is slightly higher than that. Heat treatment to the extent is frequently used.

  However, on the production line in these manufacturing fields, the substrate is usually conveyed while receiving a thermal history in the heat treatment furnace or the heating film forming apparatus, so it is difficult to directly measure the temperature of the substrate with a thermocouple, Usually, the temperature of the substrate is estimated by measuring the temperature of the atmosphere in the furnace or in the apparatus.

  If the temperature of the substrate can be measured directly and accurately, the accuracy of process control will be improved, contributing to higher performance of the product. Such a situation is commonly recognized not only in the semiconductor and liquid crystal manufacturing fields but also in many manufacturing fields.

  Measure the temperature of the object to be measured when the object to be measured cannot be used because the object to be measured is transported (that is, moved continuously), etc. One of the temperature measuring tools that can be used is a non-contact type thermometer such as a radiation thermometer.

  However, even in the case of using a non-contact type thermometer, in order to measure the thermal history received by the temperature-measured object conveyed in the heat treatment furnace, the non-contact type thermometer itself is also used for conveying the temperature-measured object. It is necessary to move them together or to install a large number of non-contact thermometers along the direction in which the object to be measured is transported, resulting in complicated facilities and excessive equipment costs. In addition, when the object to be measured is in a sealed state, it cannot be used from the outside because it cannot be observed from the outside.

  Another temperature measuring tool that does not require wiring is a seal-type temperature measuring tool. The seal-type temperature measuring instrument is a temperature measuring instrument in which a plurality of pigments that change color every predetermined temperature, such as in increments of 10 ° C or in increments of 25 ° C, are sandwiched between resins to form a seal. Although it is an excellent temperature measuring instrument, it is difficult to measure at a high temperature of 250 ° C. or more because it contains a resin member, and it also uses the melting phenomenon of the material, so that impurities are generated due to evaporation of the molten material. The use is hesitant in an environment where there is a risk of contamination of the substrate by impurities.

  Recently, a wafer sensor incorporating a temperature sensor, an IC recorder, and a battery inside the substrate has been developed. If this wafer sensor is used, the thermal history of the substrate being transferred can be measured. However, since a battery or a semiconductor element is used, the temperature range that can be measured with this substrate is limited to about 150 ° C., and it is difficult to measure a temperature higher than that.

In addition, temperature measuring tools that measure the maximum temperature without using electrical wiring are also used, such as those that use volume changes during ceramic sintering and those that use ceramic softening (Zeegel cone). However, the temperature that can be measured with a temperature measuring tool using these ceramics is for high temperatures of 800 to 1000 ° C. or higher, and is not suitable for temperature measurement at about 150 to 600 ° C. required in the field of manufacturing semiconductors and liquid crystals. .
JP-A-9-5166

  In the conventional temperature measuring device and the temperature measuring method and temperature measuring device using this temperature measuring device, no external wiring is required, no impurities or dust is generated, and in a wide temperature range from low temperature to high temperature. There was a problem that there was no one that could measure the maximum temperature reached.

  The present invention solves the above-described problems, does not require external wiring, does not generate impurities and dust, and can measure a maximum temperature in a wide temperature range from a low temperature to a high temperature. An object of the present invention is to provide a temperature measuring device and a temperature measuring method.

In order to achieve the above object, the invention according to claim 1 of the present invention provides:
In the temperature measurement member consisting of a substrate with a metal thin film in which a metal thin film having a smooth surface and a coefficient of thermal expansion different from that of the substrate is formed on a substrate having a smooth surface,
The surface roughness Ra of the substrate is 1 μm or less,
The surface roughness Ra of the metal thin film is 0.5 μm or less,
The metal thin film is a temperature measuring member having a thickness of 10 nm to 1000 μm. Thereby, the received thermal history can be left in the metal thin film based on the highest temperature of the object or atmosphere to be measured to which an arbitrary thermal history is given. Therefore, as long as you use a temperature measurement member that retains this thermal history, there is no need for external wiring, no generation of impurities and dust, and the measurement of the highest temperature achieved in a wide temperature range from low to high temperatures. Is possible.

The invention according to claim 2 is the invention according to claim 1,
The material of the substrate is any one selected from the group consisting of silicon, glass, quartz, graphite, SiC, sapphire, and resin. Accordingly, it is possible to provide a temperature measurement member that can realize optimum temperature measurement according to the condition of the object to be measured or the atmosphere.

The invention according to claim 3 is the invention according to claim 1 or 2,
The material of the metal thin film is Mg, Al, Si, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zr, Mo, Ru, Pd, Ag, In, Sn, Hf, Ta, W, Pt, Au. And one or more selected from the group consisting of Zn. Accordingly, it is possible to provide a temperature measurement member that can realize optimum temperature measurement according to the condition of the object to be measured or the atmosphere.

The invention according to claim 4 is the invention according to claims 1 to 3,
A protective film is further formed on the metal thin film. Accordingly, it is possible to provide a temperature measurement member that can realize a wider and optimum temperature measurement according to the condition of the object to be measured or the atmosphere.

The invention described in claim 5
A temperature measuring device for measuring a maximum temperature of an object or atmosphere accompanying a thermal history,
(1) A substrate with a plurality of metal thin films in which a metal thin film having a smooth surface and a thermal expansion coefficient different from that of the substrate is formed on a substrate having a smooth surface;
(2) a surface density measuring unit for measuring the surface density of the number of protrusions or recesses generated on the surface of the metal thin film after the thermal history of different maximum ultimate temperatures is given to the plurality of substrates with metal thin films, ,
(3) The surface density of the number of convex portions or concave portions obtained based on the measured value of the surface density of the number of convex portions or concave portions obtained by the surface density measuring section and the actual measurement value of the maximum temperature reached; A storage unit storing data indicating the relationship with the maximum temperature reached;
(4) The metal thin film of (1) used as a temperature measurement member set in an environment of an object to be measured or an atmosphere to be measured, which is measured by the surface density measuring unit of (2) and given an arbitrary thermal history Relationship between the surface density of the number of convex portions or concave portions generated on the surface of the metal thin film of the substrate with a metal substrate or the substrate with a metal thin film obtained under the same conditions as the above (1), and the data stored in the storage unit And a temperature calculation unit for obtaining the maximum temperature of the object to be measured or the atmosphere to which the thermal history is given. As a result, it is possible to realize a temperature measuring device that does not require external wiring, does not generate impurities and dust, and can measure the maximum temperature achieved in a wide temperature range from a low temperature to a high temperature.

The invention according to claim 6 is the invention according to claim 5,
The surface density measuring unit (2) observes the surface shape of the convex portion or the concave portion generated on the surface of the metal thin film with a microscope and captures the surface shape as an analog image signal, It is composed of an AD conversion unit for digitizing and obtaining image data, and a number calculation unit that counts only those whose diameters are within a predetermined range from the image data and converts them to the number per unit area. ing. Thereby, since excellent image data output can be obtained, it can be converted into the number (surface density) per unit area of the convex portions or concave portions to be processed using an existing excellent image processing technique.

The invention according to claim 7 is the invention according to claim 6,
The predetermined value is not less than 0.1 μm and not more than 30 μm. Thereby, the surface density of the convex part or the recessed part which generate | occur | produced on the metal thin film surface from image data can be calculated | required favorably.

The invention according to claim 8 provides:
In the method of measuring the maximum temperature of an object or atmosphere that accompanies thermal history,
(1) preparing a plurality of substrates with a metal thin film in which a metal thin film having a smooth surface and a coefficient of thermal expansion different from that of the substrate is formed on a substrate having a smooth surface;
(2) A thermal history that gives different maximum temperatures to each of the plurality of substrates with metal thin films is given,
(3) Measure the surface density of the number of convex portions or concave portions generated on the surface of the metal thin film after giving this thermal history,
(4) Based on the measured value of the surface density of the number of convex portions or concave portions and the measured value of the maximum reached temperature, the relationship between the surface density of the number of convex portions or concave portions and the maximum reached temperature is obtained,
(5) Environment of the object or atmosphere to be measured to which an arbitrary thermal history is given using the substrate with the metal thin film of (1) or the substrate with the metal thin film obtained under the same conditions as in (1) above as a temperature measurement member Set to
(6) The surface density of the number of convex portions or the number of concave portions generated on the surface of the metal thin film of the substrate with the metal thin film used as the temperature measuring member to which the arbitrary thermal history is given is measured. The maximum reached temperature of the object to be measured or the atmosphere to which the thermal history is given is determined from the relationship between the surface density of the number of protrusions or recesses obtained and the maximum reached temperature. As a result, it is possible to realize a temperature measuring method that does not require external wiring, does not generate impurities and dust, and can measure the highest temperature in a wide temperature range from a low temperature to a high temperature.

The invention according to claim 9 is the invention according to claim 8,
The step of measuring the surface density of (3) and (6) includes a step of observing the surface shape of the convex portion or the concave portion generated on the surface of the metal thin film with a microscope, and taking this surface shape as an analog image signal, It comprises a step of digitizing an image signal to obtain image data, and a step of counting only those in which the diameter of the convex portion or the concave portion falls within a predetermined range from this image data and converting it to the number per unit area. Thereby, not only the optimum observation means can be used in accordance with the surface shape of the convex portion or the concave portion generated on the surface of the metal thin film, but good image data output can be obtained from each of these observation means. Thereby, since excellent image data output can be obtained, it can be converted into the number (surface density) per unit area of the convex portions or concave portions to be processed using an existing excellent image processing technique.

The invention according to claim 10 is the invention according to claim 9,
The predetermined value is not less than 0.1 μm and not more than 30 μm. Thereby, the surface density of the convex part or the recessed part which generate | occur | produced on the metal thin film surface from image data can be calculated | required favorably.

The invention according to claim 11 is the invention according to claim 8,
The step of measuring the surface density of (3) and (6) includes the step of irradiating light on the convex portion or concave portion generated on the surface of the metal thin film, detecting the scattered light, and taking it in as an analog intensity signal, and this intensity. It comprises a step of digitizing a signal to obtain intensity data, and a step of counting only those in which the intensity data falls within a predetermined range and converting it to the number per unit area. Thereby, another temperature measurement which is not based on the image data regarding the surface shape of the convex part or the concave part observed using a microscope or the like becomes possible. Moreover, a general particle counter (common name) can be used for the process of measuring a series of said surface density.

The invention according to claim 12 is the invention according to claim 8,
The steps (3) and (6) for measuring the surface density include a step of irradiating light on a convex portion or a concave portion generated on the surface of the metal thin film, detecting the reflected light and taking it in as an analog intensity signal, and this intensity. It comprises a step of digitizing a signal to obtain intensity data, and a step of counting only those in which the intensity data falls within a predetermined range and converting it to the number per unit area. Thereby, another temperature measurement which is not based on the image data regarding the surface shape of the convex part or the concave part observed using a microscope or the like becomes possible.

As described above, the present invention
In the temperature measurement member consisting of a substrate with a metal thin film in which a metal thin film having a smooth surface and a coefficient of thermal expansion different from that of the substrate is formed on a substrate having a smooth surface,
The surface roughness Ra of the substrate is 1 μm or less,
The surface roughness Ra of the metal thin film is 0.5 μm or less,
Since the metal thin film is a temperature measuring member having a thickness of 10 nm or more and 1000 μm or less, the heat received by the metal thin film based on the highest temperature of the object or atmosphere to be measured to which an arbitrary thermal history is given. A temperature measurement member that leaves a history can be provided. Therefore, as long as you use a temperature measurement member that retains this thermal history, there is no need for external wiring, no generation of impurities and dust, and the measurement of the highest temperature achieved in a wide temperature range from low to high temperatures. Is possible.

The present invention also provides:
A temperature measuring device for measuring a maximum temperature of an object or atmosphere accompanying a thermal history,
(1) A substrate with a plurality of metal thin films in which a metal thin film having a smooth surface and a thermal expansion coefficient different from that of the substrate is formed on a substrate having a smooth surface;
(2) a surface density measuring unit for measuring the surface density of the number of protrusions or recesses generated on the surface of the metal thin film after the thermal history of different maximum ultimate temperatures is given to the plurality of substrates with metal thin films, ,
(3) The surface density of the number of convex portions or concave portions obtained based on the measured value of the surface density of the number of convex portions or concave portions obtained by the surface density measuring section and the actual measurement value of the maximum temperature reached; A storage unit storing data indicating the relationship with the maximum temperature reached;
(4) The metal thin film of (1) used as a temperature measurement member set in an environment of an object to be measured or an atmosphere to be measured, which is measured by the surface density measuring unit of (2) and given an arbitrary thermal history Relationship between the surface density of the number of convex portions or concave portions generated on the surface of the metal thin film of the substrate with a metal substrate or the substrate with a metal thin film obtained under the same conditions as the above (1), and the data stored in the storage unit Therefore, because it has a structure including a temperature calculation unit for obtaining the highest temperature of the object to be measured or atmosphere to which the thermal history is given, no external wiring is required, no impurities or dust is generated, In addition, it is possible to provide a temperature measuring device capable of measuring the highest temperature achieved in a wide temperature range from a low temperature to a high temperature.

The present invention also provides:
In the method of measuring the maximum temperature of an object or atmosphere that accompanies thermal history,
(1) preparing a plurality of substrates with a metal thin film in which a metal thin film having a smooth surface and a coefficient of thermal expansion different from that of the substrate is formed on a substrate having a smooth surface;
(2) A thermal history that gives different maximum temperatures to each of the plurality of substrates with metal thin films is given,
(3) Measure the surface density of the number of convex portions or concave portions generated on the surface of the metal thin film after giving this thermal history,
(4) Based on the measured value of the surface density of the number of convex portions or concave portions and the measured value of the maximum reached temperature, the relationship between the surface density of the number of convex portions or concave portions and the maximum reached temperature is obtained,
(5) Environment of the object or atmosphere to be measured to which an arbitrary thermal history is given using the substrate with the metal thin film of (1) or the substrate with the metal thin film obtained under the same conditions as in (1) above as a temperature measurement member Set to
(6) The surface density of the number of convex portions or the number of concave portions generated on the surface of the metal thin film of the substrate with the metal thin film used as the temperature measuring member to which the arbitrary thermal history is given is measured. Since it is configured to obtain the maximum temperature of the object to be measured or the atmosphere to which the thermal history is given from the relationship between the surface density of the number of convex portions or concave portions obtained and the maximum temperature, external wiring Is not required, impurities and dust are not generated, and a temperature measuring method capable of measuring the maximum temperature in a wide temperature range from a low temperature to a high temperature can be provided.

  Hereinafter, the present invention will be described in more detail while illustrating embodiments.

(Configuration of temperature measuring member according to the present invention)
The temperature measuring member according to the present invention is
In the temperature measurement member consisting of a substrate with a metal thin film in which a metal thin film having a smooth surface and a coefficient of thermal expansion different from that of the substrate is formed on a substrate having a smooth surface,
The surface roughness Ra of the substrate is 1 μm or less,
The surface roughness Ra of the metal thin film is 0.5 μm or less,
The metal thin film has a thickness of 10 nm to 1000 μm.

  Hereinafter, the reason for the above configuration will be described in detail.

  As is generally known, when a substrate on which a metal thin film is formed on a silicon substrate or glass substrate by vapor deposition, sputtering, plating, or the like is heated, stress is applied to the metal thin film due to the difference in thermal expansion coefficient between the substrate and the metal thin film. Join. When heating is started, first, the metal thin film is elastically deformed according to the stress caused by the difference in thermal expansion coefficient between the substrate and the metal film. Furthermore, the stress applied to the metal thin film increases as the temperature rises, and when the limit value is reached, the metal thin film undergoes plastic deformation. At this time, if the force applied to the surface of the metal thin film is in the compression direction, protrusions as projections are formed on the surface. Conversely, if a strong pulling force is applied, a hole as a recess is formed.

  Whether the stress applied to the metal thin film during heating is a compressive stress or a tensile stress is uniquely determined by the combination of the substrate and the metal thin film. For example, when an aluminum thin film is formed on a silicon substrate, since aluminum has a higher thermal expansion coefficient than silicon, compressive stress is applied to the aluminum thin film, and protrusions are formed on the surface of the aluminum thin film.

  Once the protrusions are formed on the surface, the stress of the thin film is relieved, so that the number of protrusions does not increase even if the temperature is kept constant thereafter. When the temperature is further increased, a compressive stress due to the difference in thermal expansion coefficient is generated, and the protrusion is formed again. When heating is finished and the substrate is cooled, the stress applied to the thin film is usually applied in the opposite direction to that during heating, but the protrusions once formed do not disappear and become smooth. It remains even after cooling to room temperature.

  Here, in order to make a metal thin film formed on a substrate as described above practical as a temperature measuring member, the number of protrusions formed on the thin film surface depends only on the maximum temperature reached. Therefore, it is desirable not to depend on the heating rate or the holding time at a constant temperature.

  However, it has been unclear whether the number of protrusions generated so far depends only on the maximum temperature reached and on the rate of temperature rise and the temperature holding time. Usually, the occurrence of protrusions is considered to vary greatly depending on the film forming conditions and the type of substrate, and the number of protrusions being measured is considered to vary depending on the experimental conditions. In general, metal thin films have defects due to vacancies and impurities, and it is thought that the defects diffuse by heat treatment. The diffusion phenomenon proceeds if the temperature is kept constant for a long time. To do. When the influence of such a diffusion phenomenon is large and greatly affects the generation of protrusions due to heat treatment, the number of protrusions formed may change even if the temperature is maintained. In such a case, it is difficult to apply the protrusion generation phenomenon to temperature measurement. Further, if the defect diffusion rate is about the same as the heating rate, the generation of protrusions may greatly depend on the heating rate.

  Therefore, the present inventors have used this in which the film quality of the metal thin film formed on the substrate is strictly controlled, and by counting the number of protrusions on the metal thin film generated by heating, this protrusion formation phenomenon is achieved. The following investigation was conducted to determine whether it could be applied to temperature measurement.

  First, as a result of investigating the relationship between the formation speed of the protrusions and the heating rate in detail, the protrusion formation is a phenomenon that is temporally fast. If the heating rate is 1000 ° C. or less per minute, It was found that the number was hardly affected by the heating rate. Next, after reaching a temperature at which the protrusions were formed, an experiment was conducted in which the temperature rise was stopped and maintained at that temperature for a long time. As a result, it was found that there was no increase in the number of protrusions while maintaining a constant temperature. Such a phenomenon is a phenomenon found for the first time by controlling the film forming conditions of the metal thin film formed on the substrate appropriately and strictly. As described above, when the temperature measuring member including the metal thin film is used, the number of protrusions formed on the surface of the metal thin film per unit area and the maximum applied temperature regardless of the heating rate and the constant temperature holding time. It is thought that there can be a certain relationship between. More specifically, if the deposition conditions of the metal thin film change, the particle size of the metal thin film changes, and the size of this particle size causes the plastic thin film to deform and the number of protrusions generated during heating. To affect.

  Furthermore, it was found that when a substrate having a predetermined thickness and surface roughness and the type of metal thin film to be combined therewith were determined and a metal thin film was formed under predetermined film forming conditions, the film thickness and surface roughness were uniquely determined. . In addition, when the temperature measuring member prepared in this way is used, the surface temperature information (observed with a microscope) that is caused by the highest temperature applied to the temperature measuring member and the convex portion or concave portion formed on the surface of the metal thin film. It has also been found that there is a certain relationship between the calculated number per unit area based on the image data of the surface shape of the protrusions or recesses, the intensity of scattered light, and the intensity of reflected light.

  Hereinafter, as a representative example of the temperature measuring member, a film forming condition when a silicon substrate is used as the substrate and aluminum is used as the metal thin film will be described.

  In the case of pure aluminum, a resistance heating vapor deposition method or an electron beam heating vapor deposition method is often used as a thin film forming method. However, with this method, the surface of the aluminum is severely uneven due to heat during film formation, and the film surface becomes cloudy. Since the temperature measuring method of the present invention using the temperature measuring member is based on observing protrusions as convex portions generated by heat treatment, the surface of the film is not yet subjected to thermal history immediately after film formation. Roughening is not desirable. In short, the surface roughness of the film must be small and smooth. Therefore, the vapor deposition method is not suitable for aluminum film formation.

In order to form a film so that the surface of the aluminum thin film becomes smooth, it is necessary to form the film by a low temperature process, and a sputtering method is suitable as the method. However, even in this method, when the film formation power is high or the film formation time is long, the aluminum surface easily becomes uneven and becomes clouded. For example, in magnetron sputtering, the ultimate vacuum is 1.2 × 10 ⁻⁶ Torr, the distance between substrate targets is 50 mm, the deposition gas is Ar, the deposition gas pressure is 10 mTorr, and the deposition power is 15 W / cm ² . When an aluminum thin film having a thickness of 1 μm is formed on a silicon wafer as a substrate having a thickness of 0.35 mm, the film surface becomes clouded. On the other hand, an aluminum thin film having a thickness of 300 nm was formed on a 0.35 mm thick silicon wafer under the conditions of a distance between substrate targets of 100 mm, a film forming gas pressure of 2 mTorr, and a film forming power of 2 W / cm ^2. By performing the step, a film having a smooth surface can be obtained. As described above, in order to obtain an aluminum thin film having a smooth surface, film formation at low power and low temperature is required. The maximum allowable film forming power is 10 W / cm ² , and the allowable film forming temperature is 100 ° C. or less (temperature increase at room temperature film forming).

  In view of the technical idea of the present invention, various things other than the combination of the silicon substrate and the aluminum thin film are conceivable. The following is introduced as an example.

  The types of substrate materials are silicon, glass, quartz, graphite, SiC, sapphire, and resin. The surface roughness of these substrates only needs to be smoother than the unevenness of the metal thin film generated by the received heat history, and since it is extremely difficult to produce a substrate with a surface roughness of 5 nm or less, for example, the surface roughness Ra of the substrate May be 5 nm or more and 1 μm or less. This makes it possible to collect well the number of convex portions or concave portions formed on the surface of the metal thin film due to the thermal history received by the temperature measuring member comprising the metal thin film substrate from the object or atmosphere to be measured, which will be described in detail later. Can do. In addition, an optimal temperature measurement method can be realized by appropriately selecting the type of substrate material according to the conditions of the object to be measured or the atmosphere.

  The types of metal thin film materials are Mg, Al, Si, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zr, Mo, Ru, Pd, Ag, In, Sn, Hf, Ta, W, Pt, Au Zn, and the thickness of these metal thin films is 10 nm or more and 1000 μm or less. Since it is extremely difficult to produce a metal thin film having a surface roughness Ra of 5 nm or less, the surface roughness Ra of the metal thin film is 5 nm to 0.5 μm. By adopting this film thickness and surface roughness, the convex part formed on the surface of the metal thin film by the thermal history received by the temperature measuring member consisting of the substrate with the metal thin film from the object or atmosphere to be measured, which will be described in detail later. Alternatively, the number of recesses can be collected well. Further, an optimal temperature measurement method can be realized by appropriately selecting the type of metal thin film material according to the conditions of the object to be measured or the atmosphere. The metal thin film material is preferably a pure metal. However, if the metal thin film material contains impurities, the metal film may contain impurities as long as precipitation proceeds sufficiently and does not affect, for example, the formation behavior of protrusions as protrusions.

  The film forming conditions other than the aluminum thin film will be described a little below.

In the case of a copper (Cu) thin film, a copper oxide film is thick and easy to grow. Therefore, in order to form a film having a smooth surface, it is necessary to form a low-temperature film in a high vacuum. Even when the film is formed by the magnetron sputtering method, if the degree of vacuum is poor, the surface is easily oxidized and roughened. Therefore, it is necessary that the ultimate vacuum is 1 × 10 ⁻⁷ Torr or less. In the case of a pure copper thin film formed on a silicon substrate with a thickness of 800 nm, a plastic change of the surface appears at 250 ° C. or higher, and oxidation does not proceed up to 500 ° C., so that it can be used as a temperature measuring member. If the temperature is higher than that, oxidation tends to proceed and measurement is difficult. The copper thin film is suitable for measurement in a slightly higher temperature and high vacuum atmosphere than the aluminum thin film.

  In the case of tin (Sn), a smooth film cannot be formed even if the film is formed with low power by sputtering. However, in the case of tin, the protrusions that can be heated are huge whiskers that can reach several millimeters, so even if the initial surface of the film is not very smooth, the temperature can be measured by measuring the protrusions in a special environment. It is. For example, it is suitable for measurement in the range of about 100 ° C. to 300 ° C. in an environment with a lot of dust.

  Zinc (Zn) is a metal that is easily sublimated, so it can cause contamination of the surrounding environment during heating, so it is hesitant to use it in a high vacuum environment that hate contamination (contamination). It is suitable for use under processes where Zn is used in large quantities, such as hot-dip Zn plating.

  In general, metals such as Sn, Zn, and indium (In), which have a low melting point, can measure the maximum temperature when subjected to a thermal history at a low temperature (especially 70 ° C. or more and 200 ° C. or less), and 150 ° C. Aluminum, copper, etc. are suitable for the measurement of the highest temperature achieved when receiving a thermal history up to about 500 ° C. In addition, for metals such as tungsten (W) and tantalum (Ta) having a high melting point, it is possible to measure the maximum temperature achieved when a thermal history at a higher temperature (especially 250 ° C. or higher and 700 ° C. or lower) is received. In addition, by appropriately combining the metals described above, it is possible to measure the maximum temperature reached corresponding to various temperature regions. Further, if a silver (Ag) thin film is selected, a resin can be used as the substrate. However, when light is irradiated at the interface between Ag and the resin, Ag oxidation and reduction occur simultaneously, causing Ag aggregation and Ag intrusion into the resin, which must be avoided. Therefore, as described above, these can be appropriately selected and used as necessary according to the conditions of the object to be measured or the atmosphere.

The temperature measuring member of the present invention described in detail above collects the number of convex portions or concave portions formed on the surface of the metal thin film by the thermal history received from the object or atmosphere to be measured, as will be described in detail later. It is used for the method of measuring temperature. However, when this temperature measuring member is heated in an air atmosphere, the surface of the metal thin film of the temperature measuring member may be oxidized and the surface state may change significantly. For example, when the metal thin film is a copper (Cu) thin film, when heated in an air atmosphere, a surface oxide starts to be formed at 200 ° C. or higher, and the surface oxide covers the desired unevenness. It becomes difficult. In such a case, oxidation of the metal surface can be suppressed by forming a surface protective film having a thickness of 20 nm to 2 μm on the metal thin film. As the surface protective film, any oxide film that is stable at a desired temperature state can be used, but Al ₂ O ₃ , SiO ₂ , MgO, ZrO ₂ , HfO ₂ , TiO ₂ , Cr ₂ O _{3 can be used.} NiO, ZuO, In ₂ O ₃ and Y ₂ O ₃ are convenient. These protective films can be formed by PVD methods such as sputtering or vapor deposition. This protective film is not preferable if the film thickness is 20 nm or less because pinholes cannot be avoided. Moreover, since a crack generate | occur | produces in a protective film with a film thickness of 2 micrometers or more, it is unpreferable. Therefore, a protective film having a thickness of 30 nm to 300 nm is preferable.

(Temperature measuring device and temperature measuring method according to the present invention)
The temperature measuring device according to the present invention is
A temperature measuring device for measuring a maximum temperature of an object or atmosphere accompanying a thermal history,
(1) A substrate with a plurality of metal thin films in which a metal thin film having a smooth surface and a thermal expansion coefficient different from that of the substrate is formed on a substrate having a smooth surface;
(2) a surface density measuring unit for measuring the surface density of the number of protrusions or recesses generated on the surface of the metal thin film after the thermal history of different maximum ultimate temperatures is given to the plurality of substrates with metal thin films, ,
(3) The surface density of the number of convex portions or concave portions obtained based on the measured value of the surface density of the number of convex portions or concave portions obtained by the surface density measuring section and the actual measurement value of the maximum temperature reached; A storage unit storing data indicating the relationship with the maximum temperature reached;
(4) The metal thin film of (1) used as a temperature measurement member set in an environment of an object to be measured or an atmosphere to be measured, which is measured by the surface density measuring unit of (2) and given an arbitrary thermal history Relationship between the surface density of the number of convex portions or concave portions generated on the surface of the metal thin film of the substrate with a metal substrate or the substrate with a metal thin film obtained under the same conditions as the above (1), and the data stored in the storage unit And a temperature calculation unit for obtaining a maximum temperature of the object or atmosphere to be measured to which a thermal history is given.

Moreover, the temperature measurement method according to the present invention includes:
In the method of measuring the maximum temperature of an object or atmosphere that accompanies thermal history,
(1) preparing a plurality of substrates with a metal thin film in which a metal thin film having a smooth surface and a coefficient of thermal expansion different from that of the substrate is formed on a substrate having a smooth surface;
(2) A thermal history that gives different maximum temperatures to each of the plurality of substrates with metal thin films is given,
(3) Measure the surface density of the number of convex portions or concave portions generated on the surface of the metal thin film after giving this thermal history,
(4) Based on the measured value of the surface density of the number of convex portions or concave portions and the measured value of the maximum reached temperature, the relationship between the surface density of the number of convex portions or concave portions and the maximum reached temperature is obtained,
(5) Environment of the object or atmosphere to be measured to which an arbitrary thermal history is given using the substrate with the metal thin film of (1) or the substrate with the metal thin film obtained under the same conditions as in (1) above as a temperature measurement member Set to
(6) The surface density of the number of convex portions or the number of concave portions generated on the surface of the metal thin film of the substrate with the metal thin film used as the temperature measuring member to which the arbitrary thermal history is given is measured. The maximum attainable temperature of the object or atmosphere to be measured, to which the thermal history is given, is obtained from the relationship between the surface density of the number of protrusions or recesses obtained and the maximum attainable temperature.

Hereinafter, for this temperature measurement method, a film thickness of 300 nm is formed on a silicon wafer having a thickness of 0.35 mm under the conditions of a distance between substrate targets of 100 mm, a film forming gas pressure of 2 mTorr, and a film forming power of 2 W / cm ² . A case where a plurality of substrates with metal thin films on which an aluminum thin film is formed is prepared and temperature measurement is performed using the plurality of substrates with metal thin films will be described in detail.

First, regarding the plurality of substrates with metal thin films, it is necessary to examine in advance the area density measuring unit described in detail below the relationship between the maximum temperature reached and the number of protrusions formed as protrusions formed on the surface of the metal thin film at this temperature. There is. Further, the surface density measuring unit includes a surface information collecting unit, an AD converting unit, and a number calculating unit. Therefore, the substrate with the metal thin film was placed in a small vacuum heat treatment furnace and heated to a predetermined temperature at a temperature rising rate of 5 ° C./min. The surface shape of the protrusion formed on the surface of the metal thin film of the substrate with the metal thin film after heating was observed with a microscope, and the surface shape was captured by a CCD camera constituting the surface information collecting unit to obtain an analog image signal. This image signal was digitized by an IO board as an AD conversion unit to obtain image data. Next, this image data is binarized using a number calculation unit, and only the number corresponding to the projection diameter (0.3 μm or more and 10 μm or less) in the predetermined value range (hereinafter referred to as surface density and area density). Calculated). As a result, protrusions having a diameter of 0.3 μm or more and 10 μm or less began to occur at 150 ° C. Protrusions having a surface density of 20 × 10E9 / m ² were generated at 200 ° C., and protrusions having a surface density of 60 × 10E9 / m ² were generated at 300 ° C. Therefore, in this example, it was found that there is a relationship of the following formula (1) between the maximum temperature reached (T) and the surface density (X × 10E9 / m ² ).

  T = 0.4 × X-60 (150 to 300 ° C.)-Formula (1)

Moreover, after heating at a temperature increase rate of 50 ° C./min and 100 ° C./min, respectively, the result of determining the relationship between the maximum temperature reached (T) and the surface density (X × 10E9 / m ² ) by the same method as above. Was the same as the above formula (1). Further, after heating to 300 ° C. at a rate of temperature increase of 50 ° C./min and holding it for 30 minutes, the result of investigating the above relationship was also the same as the above formula (1). Moreover, the result of examining the relationship between the maximum temperature reached (T) and the surface density (X × 10E9 / m ² ) by changing the atmosphere into argon gas, nitrogen gas, or air is the above formula (1). Was the same.

Next, an aluminum thin film having a thickness of 300 nm is formed on a silicon wafer having a thickness of 0.35 mm under the conditions of a distance between substrate targets of 100 mm, a film forming gas pressure of 5 mTorr, and a film forming power of 2 W / cm ^2. A plurality of prepared substrates with metal thin films were prepared. As a result of examining the relationship between the maximum ultimate temperature (T) and the surface density (X × 10E9 / m ² ) after heating to 300 ° C. at a rate of temperature increase of 5 ° C./min using the substrate with the metal thin film. Was found to have the relationship of equation (2).

  T = 0.3 × −45 (150 ° C. or more and 300 ° C. or less)-Formula (2)

Next, an aluminum thin film having a thickness of 100 nm is formed on a silicon wafer having a thickness of 0.35 mm under the conditions of a distance between substrate targets of 100 mm, a film forming gas pressure of 5 mTorr, and a film forming power of 2 W / cm ^2. A plurality of prepared substrates with metal thin films were prepared. As a result of examining the relationship between the maximum ultimate temperature (T) and the surface density (X × 10E9 / m ² ) after heating to 300 ° C. at a rate of temperature increase of 5 ° C./min using the substrate with the metal thin film. Was found to have the relationship of equation (3).

  T = 0.13 × X-19.5 (150 ° C. or more and 300 ° C. or less)-formula (3)

Thus, when the film formation conditions change, the number of protrusions generated changes. Therefore, the type, dimensions, surface roughness, and film formation conditions of the material constituting the metal thin film-attached substrate must be strictly controlled so as to have predetermined values. However, as long as the above management is observed, it does not depend on the rate of temperature rise, the temperature holding time, or the atmosphere gas, and is constant between the maximum temperature reached (T) and the surface density (X × 10E9 / m ² ). The relational expression is established.

Therefore, if the data indicating the relationship between the maximum temperature (T) and the surface density (X × 10E9 / m ² ) determined in advance for the substrate with the metal thin film is stored in a memory serving as a storage unit, It is possible to obtain the maximum temperature of the object or atmosphere to be measured, to which the thermal history is applied, from the processing steps described in (1).

  As the next procedure, the substrate with metal thin film or the substrate with metal thin film obtained under the same conditions as the substrate with metal thin film is used as a temperature measurement member to be placed in the environment of the object to be measured or the atmosphere to be measured. set. Then, the surface density of the number of protrusions generated on the surface of the metal thin film of the substrate with the metal thin film used as the temperature measuring member to which the arbitrary thermal history is given is measured by the same surface density measuring unit as described above. From the relationship between the measured value and the data stored in the above-described memory, it is possible to obtain the maximum temperature of the object or atmosphere to be measured, to which the thermal history is given, using the temperature calculation unit.

  In the present embodiment, an example in which silicon is used as the substrate and aluminum is used as the metal thin film formed on the substrate has been described in detail. However, the embodiment is not necessarily limited thereto.

  As described above in the configuration of the temperature measurement member according to the present invention, surface information caused by protrusions as protrusions or holes as recesses by various combinations of a substrate and a metal thin film formed thereon. Can be used to measure the maximum temperature reached.

  Further, in the present embodiment, an example in which an image signal as surface information resulting from protrusions formed on the surface of a metal thin film is captured by a surface information collecting unit configured by an optical microscope and a CCD camera has been described. In addition, although an example has been described in which digitized image data using an IO board is binarized by a number calculation unit to obtain the number of protrusions per unit area (surface density), the present invention is not necessarily limited thereto. is not. For example, a laser microscope can be used as the microscope. Thereby, the number of protrusions having a diameter of 0.1 μm or more can be measured. Further, by using an electron microscope such as an SEM (scanning electron microscope), even smaller protrusions and holes can be observed and collected as image information. In addition, by using a contact-type roughness meter as a surface information collecting unit, it is possible to directly measure minute protrusions and calculate the surface density based on the data. In addition to this, for example, as surface information caused by protrusions formed on the surface of the metal thin film, the intensity of scattered light is collected, and the number calculation unit only determines the intensity of scattered light per unit area within a predetermined range. It is also possible to use a device (so-called particle counter) that obtains the number of particles. Further, the intensity of the reflected light can be used as the surface information. By using this intensity, it is possible to use a principle used in a particle counter (for example, only the intensity within a predetermined value range is obtained as the number per unit area (surface density)).

  In the calculation of the number of protrusions of the metal thin film caused by heating, if the diameter of the protrusions (protrusions) is less than 0.1 μm, it is difficult to measure the reflectivity, detect with a particle counter or laser microscopy. Moreover, when the diameter of a convex part exceeds 30 micrometers, since distribution of the convex part in a surface is not uniform, the temperature measurement by the measurement of a micro part becomes difficult. From these points, except when using an electron microscope such as SEM, the temperature is measured using a convex portion having a diameter in the range of 0.1 μm to 30 μm. In addition, since a huge convex part appears mainly when heating temperature becomes higher than a desired measurement area | region, in order to perform uniform and favorable temperature measurement, a convex part or concave part with a diameter of 0.3 micrometer-10 micrometers It is preferable to measure the temperature in the region where appears.

A thickness of 0 was achieved under the conditions of an ultimate vacuum of 1.2 × 10 ⁻⁶ Torr, a distance between substrate targets of 100 mm, an argon gas pressure of 2 mTorr, and a deposition power of 2 W / cm ² by sputtering. A substrate with a metal thin film was prepared by forming an aluminum thin film having a purity of 99.99 with a thickness of 300 nm on a .35 mm, 2-inch silicon wafer. The substrate with the metal thin film was used and heated in an argon atmosphere at a heating temperature of 5 ° C./min. The surface shape of the protrusion formed on the surface of the metal thin film of the substrate with the metal thin film after heating was observed with a microscope, and the surface shape was captured by a CCD camera constituting the surface information collecting unit to obtain an analog image signal. This image signal was digitized by an IO board as an AD conversion unit to obtain image data. Next, this image data is binarized using a number calculating unit, and only those corresponding to the projection diameter (0.3 μm or more and 10 μm or less) within the predetermined value range are calculated as the number per unit area (surface density). did. As a result, it was found that there is a relationship of the following formula (4) between the maximum temperature reached (T) and the surface density (X × 10E9 / m ² ).

  T = 0.4 × X-60--Formula (4)

  A temperature measuring member made of a substrate with a metal thin film prepared under the same conditions as described above is installed in a vacuum heat treatment furnace, and the temperature rising rate is 10 ° C./min in the vacuum atmosphere, the target maximum temperature in the furnace is 250 ° C., and the holding time is 30 minutes. The heating test was conducted with the setting of. At this time, the temperature of the temperature measuring member was simultaneously measured with a thermocouple. As a result, the temperature measuring member actually reached 250 ° C., then reached 280 ° C. after 3 minutes, and then the temperature dropped and stabilized at 250 ° C. after 10 minutes.

When the surface density of the protrusions on the surface of the metal thin film of the temperature measurement member after the heating test was determined using the same means as described above, it was 52 × 10E-9 / m ² . Therefore, when converted into temperature using the above formula (4), it was 280 ° C. The result of having observed the shape of the metal thin film surface at this time with the microscope is shown in FIG.

Next, using the vacuum heat treatment furnace as the object to be measured or atmosphere to which the thermal history is given, the temperature rising rate is set to 10 ° C./min in the nitrogen atmosphere, the target maximum temperature is 250 ° C., and the holding time is set to 30 minutes. A heating test was performed. At this time, the temperature measuring device did not reach 250 ° C., and reached 230 ° C. after 3 minutes and stabilized at 200 ° C. after 10 minutes. When the surface density of the protrusions on the surface of the metal thin film of the temperature measuring member after cooling was determined using the same means as described above, it was 30 × 10E-9 / m ² . Therefore, when converted into temperature using the above formula (4), it was 225 ° C. Thus, if the said temperature measurement member is used, the measurement of the highest ultimate temperature of the arbitrary locations in a furnace is possible.

  The method for measuring the maximum temperature and the temperature measuring apparatus described briefly in the first embodiment will be described below. FIG. 2 is a block diagram for explaining the temperature measuring apparatus in the present embodiment.

In FIG. 2, reference numeral 1 denotes a temperature measuring member which is set in a vacuum heat treatment furnace as an object to be measured shown in the first embodiment and is provided with a metal thin film substrate to which a thermal history is given, and 2 is a holding base for supporting the temperature measuring member 1. 3 is an optical microscope for observing the shape of protrusions on the surface of the metal thin film, 4 is attached to the optical microscope 3, and is a CCD camera for outputting an analog image signal. 5 is an image obtained by digitizing the output signal of the CCD camera 4. An IO board for outputting data, 6 is an arithmetic processing device to which the IO board is connected, 7 is a binarization process for digitized image data output from the IO board 5, and the diameter of the protrusion in the predetermined value range The number calculating unit for counting only those corresponding to the above, and calculating the surface density (X × 10E9 / m ² ), 8 is obtained in advance by giving a thermal history by preliminary experiments on the substrate with metal thin film. A memory serving as a storage unit storing data on the maximum temperature (T) and surface density (X × 10E9 / m ² ), 9 received a thermal history from the vacuum heat treatment furnace to be measured From the surface density calculated by using the number calculating section 7 for the temperature measuring member 1 and the data on the maximum temperature (T) and the surface density (X × 10E9 / m ² ) stored in the memory 8, the vacuum heat treatment furnace The temperature calculation unit 10 for obtaining the highest temperature (T) of the first display 10 is a display unit for displaying the temperature obtained by the temperature calculation unit 9.

  Using means such as the optical microscope 3, the projection shape on the surface of the metal thin film is observed, the surface shape is captured as an analog image signal by the CCD camera 4, and digital image data output is obtained by the IO board 5. The data output is very good. In addition, by using the CCD camera 4, the IO board 5 and the number calculation unit 7, an existing excellent image processing method can be utilized.

By sputtering, the ultimate vacuum is 1.2 × 10 ⁻⁶ Torr, the distance between substrate targets is 100 mm, the argon gas pressure during film formation is 3 mTorr, and the film formation power is 2.8 W / cm ^2. A substrate with a metal thin film was prepared by forming an aluminum thin film having a thickness of 300 nm and a purity of 99.99 on a 0.625 mm, 6-inch silicon wafer.

Next, the substrate with the metal thin film was heat-treated in a vacuum heat treatment furnace. The rate of temperature increase at that time was 5 ° C./min, the temperature was raised to a predetermined temperature, held for 10 minutes, and then naturally cooled. At this time, the temperature of the central portion of the substrate with the metal thin film was measured with a temperature measuring wafer with a thermocouple manufactured by Sensorray Co., Ltd., and the maximum temperature reached was recorded. Further, the number of protrusions formed on the surface of the metal thin film constituting the metal thin film-coated substrate after the heat treatment was measured with a particle counter manufactured by Topcon Corporation. Here, the number of protrusions per wafer (hereinafter referred to as the number of particles) refers to the one having a diameter of 1 μm measured on the entire surface of a 6-inch wafer. Table 1 shows the temperature reached and the number of particles of the substrate with the metal thin film thus obtained.

  FIG. 3 shows a characteristic diagram showing the relationship between the substrate temperature and the number of particles. It was found from the characteristic diagram shown in FIG. 3 that there is a relationship of the following equation (5) between the maximum temperature (T) of the substrate obtained and the number of particles (n). If the data expressed by the equation (5) is stored in the storage unit, it can be used in the following temperature measurement algorithm.

  n = 225 × T−34645—the formula (5)

  FIG. 4 is a distribution diagram showing the relationship between the distribution of the protrusions of the metal thin film on the 6-inch wafer obtained by the particle counter and the maximum temperature reached by the substrate.

  The particle counter described above corresponds to the surface density measurement unit described so far. Therefore, the measuring method and temperature measuring device for the maximum temperature described in the second embodiment can be applied to the subsequent processing methods and configurations. Therefore, detailed description is omitted.

  As described above, according to the present invention, there is no need for external wiring, no generation of impurities and dust, and a temperature measuring member and a temperature measuring device capable of measuring the maximum temperature in a wide temperature range from low to high temperatures. And a temperature measurement method can be provided.

It is a top view which shows the mode of the metal thin film surface after heat processing in Example 1. FIG. It is a block diagram for demonstrating the temperature measuring apparatus in Example 2. FIG. FIG. 10 is a characteristic diagram showing a relationship between a substrate arrival temperature and the number of particles in Example 3. In Example 3, it is a distribution map which shows the relationship between distribution of the processus | protrusion of a metal thin film, and the highest ultimate temperature of a board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Temperature measurement member 2 Holding stand 3 Optical microscope 4 CCD camera 5 IO board 6 Arithmetic processing device 7 Number calculation part 8 Memory 9 Temperature calculation part 10 Display part

Claims (12)

In the temperature measurement member consisting of a substrate with a metal thin film in which a metal thin film having a smooth surface and a coefficient of thermal expansion different from that of the substrate is formed on a substrate having a smooth surface,
The surface roughness Ra of the substrate is 1 μm or less,
The surface roughness Ra of the metal thin film is 0.5 μm or less,
The temperature measurement member whose film thickness of the said metal thin film is 10 nm or more and 1000 micrometers or less.   2. The temperature measuring member according to claim 1, wherein the material of the substrate is any one selected from the group consisting of silicon, glass, quartz, graphite, SiC, sapphire, and resin.   The material of the metal thin film is Mg, Al, Si, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zr, Mo, Ru, Pd, Ag, In, Sn, Hf, Ta, W, Pt, Au. The temperature measuring member according to claim 1 or 2, comprising at least one selected from the group consisting of Zn and Zn.   The temperature measuring member according to claim 1, wherein a protective film is further formed on the metal thin film. A temperature measuring device for measuring a maximum temperature of an object or atmosphere accompanying a thermal history,
(1) A substrate with a plurality of metal thin films in which a metal thin film having a smooth surface and a thermal expansion coefficient different from that of the substrate is formed on a substrate having a smooth surface;
(2) a surface density measuring unit for measuring the surface density of the number of protrusions or recesses generated on the surface of the metal thin film after the thermal history of different maximum ultimate temperatures is given to the plurality of substrates with metal thin films, ,
(3) The surface density of the number of convex portions or concave portions obtained based on the measured value of the surface density of the number of convex portions or concave portions obtained by the surface density measuring section and the actual measurement value of the maximum temperature reached; A storage unit storing data indicating the relationship with the maximum temperature reached;
(4) The metal thin film of (1) used as a temperature measurement member set in an environment of an object to be measured or an atmosphere to be measured, which is measured by the surface density measuring unit of (2) and given an arbitrary thermal history Relationship between the surface density of the number of convex portions or concave portions generated on the surface of the metal thin film of the substrate with a metal substrate or the substrate with a metal thin film obtained under the same conditions as the above (1), and the data stored in the storage unit And a temperature calculation unit for obtaining a maximum temperature of the object to be measured or the atmosphere to which the thermal history is given.   The surface density measuring unit (2) observes the surface shape of the convex portion or the concave portion generated on the surface of the metal thin film with a microscope and captures the surface shape as an analog image signal, An AD conversion unit for digitizing and obtaining image data, and a number calculation unit for counting only those whose diameters of convex portions or concave portions fall within a predetermined range from the image data and converting them into a number per unit area Item 6. The temperature measuring device according to Item 5.   The temperature measuring apparatus according to claim 6, wherein the predetermined value is not less than 0.1 μm and not more than 30 μm. In the method of measuring the maximum temperature of an object or atmosphere that accompanies thermal history,
(1) preparing a plurality of substrates with a metal thin film in which a metal thin film having a smooth surface and a coefficient of thermal expansion different from that of the substrate is formed on a substrate having a smooth surface;
(2) A thermal history that gives different maximum temperatures to each of the plurality of substrates with metal thin films is given,
(3) Measure the surface density of the number of convex portions or concave portions generated on the surface of the metal thin film after giving this thermal history,
(4) Based on the measured value of the surface density of the number of convex portions or concave portions and the measured value of the maximum reached temperature, the relationship between the surface density of the number of convex portions or concave portions and the maximum reached temperature is obtained,
(5) Environment of the object or atmosphere to be measured to which an arbitrary thermal history is given using the substrate with the metal thin film of (1) or the substrate with the metal thin film obtained under the same conditions as in (1) above as a temperature measurement member Set to
(6) The surface density of the number of convex portions or the number of concave portions generated on the surface of the metal thin film of the substrate with the metal thin film used as the temperature measuring member to which the arbitrary thermal history is given is measured. A temperature measuring method characterized in that a maximum attained temperature of the object or atmosphere to be measured, to which a thermal history is given, is obtained from the relationship between the surface density of the number of obtained protrusions or depressions and the maximum attained temperature.   The step of measuring the surface density of (3) and (6) includes a step of observing the surface shape of the convex portion or the concave portion generated on the surface of the metal thin film with a microscope, and taking this surface shape as an analog image signal, 9. The method according to claim 8, comprising: a step of digitizing an image signal to obtain image data; and a step of counting only those in which the diameter of the convex portion or the concave portion falls within a predetermined range from this image data and converting it into a number per unit area. The temperature measuring method described.   The temperature measurement method according to claim 9, wherein the predetermined value is 0.1 μm or more and 30 μm or less.   The step of measuring the surface density of (3) and (6) includes the step of irradiating light on the convex portion or concave portion generated on the surface of the metal thin film, detecting the scattered light, and taking it in as an analog intensity signal, and this intensity. 9. The temperature measuring method according to claim 8, comprising: a step of digitizing a signal to obtain intensity data; and a step of counting only those in which the intensity data falls within a predetermined value range and converting it to a number per unit area.   The steps (3) and (6) for measuring the surface density include a step of irradiating light on a convex portion or a concave portion generated on the surface of the metal thin film, detecting the reflected light and taking it in as an analog intensity signal, and this intensity. 9. The temperature measuring method according to claim 8, comprising: a step of digitizing a signal to obtain intensity data; and a step of counting only those in which the intensity data falls within a predetermined value range and converting it to a number per unit area.

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