TW201335449A - Heat treatment method of solid phase raw material and device thereof, and method of producing ingot, article and solar cell - Google Patents

Abstract

Provided is a heat treatment method of a solid phase raw material which heats and melts a solid phase raw material placed in a container by a heating means, then solidifies the solid phase raw material in order to obtain an ingot thereof, wherein the temperature of the solid phase raw material is detected by a temperature detecting means, and, when the temperature which remains constant just before melting of the solid phase raw material is completed is defined as a reference temperature Tm DEG C, temperature control is carried out on the basis of the reference temperature Tm DEG C.

Description

Method for heat-treating solid phase raw material and device thereof, and method for manufacturing ingot, processed product and solar battery

The present invention relates to a method and apparatus for heat treatment of a solid phase raw material, and an ingot, a processed product and a method of manufacturing the same. More specifically, the present invention relates to a heat treatment method for a solid phase raw material, a heat treatment device for the solid phase raw material thereof, and an ingot (casting material) such as a bismuth ingot, a processed product, and a method for producing a solar battery.

As a substitute for petroleum and other problems that cause various problems in the global environment, the use of natural energy is attracting attention. Among them, solar cells do not require large equipment, and do not generate noise during operation, and therefore are particularly actively introduced in Japan or Europe.

Solar cells using compound semiconductors such as cadmium telluride are also partially put into practical use, but in terms of the safety of the substance itself, previous performance, and cost performance, solar cells using polycrystalline germanium substrates and single crystal germanium substrates are used. The battery has a large share.

Not only the above-mentioned ruthenium, but also a III-VI compound such as lanthanum or gallium arsenide, a II-VI compound such as zinc selenide, a semiconductor material such as another II-IV-V2 group compound or a group I-III-VI2 compound, and a brittle material. It is easy to break, and when used as a material for a solar cell, the quality caused by the misalignment is significantly reduced. Therefore, when these materials are produced by casting such as crystal growth, the control of temperature conditions is important.

Further, when the metal material or the insulating material produced by casting is adjusted to a desired crystal grain size, the temperature condition is the same as that of the semiconductor material. The control is also more important.

For example, when a polycrystalline silicon ingot for a solar cell is produced by a casting method, a container in which a solid phase raw material is filled is usually placed in a device, and the solid phase raw material is heated and melted by a heater to lower the bottom of the container. The temperature of the side is such that the molten solid phase raw material solidifies in one direction from the bottom to the upper portion of the container, thereby producing a polycrystalline ingot for solar cells.

For example, in Japanese Patent Laid-Open Publication No. 2008-063194 (Patent Document 1), it is disclosed that a small amount of ruthenium is added to a raw material for the purpose of improving the characteristics of a polycrystalline silicon solar cell, and the bottom surface of the container is formed at the initial stage of crystal growth. The temperature was maintained at 1410 ° C for 40 minutes to grow (express) the dendritic crystal extending in the <112> direction at the lowermost portion of the ingot block.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2008-063194

However, in the temperature control of Patent Document 1, the absolute value of 1410 ° C which is the melting point of yttrium has a large meaning, and there is a time-dependent deterioration of a temperature detecting device such as a thermocouple or a radiation thermometer, a setting position thereof, or a temperature calibration method. Since various deviation factors such as variations occur, it is extremely difficult to reproduce polycrystalline germanium with good reproducibility. Further, in Patent Document 1, no specific countermeasure against the deviation factor is disclosed.

Moreover, it is not limited to enamel. In many cases, when casting semiconductor materials, metal materials, and insulator materials, and crystal growth, it is also urgently required in many cases. The absolute value of the temperature of the material itself is controlled by the accuracy of the measurement accuracy exceeding the absolute value of the detected temperature of the temperature detecting device. Especially in the case where the cast material is a brittle material, the temperature control during heat treatment requires high precision.

An object of the present invention is to provide a method for eliminating a variation in a setting state, a deterioration state, a calibration method, and the like of a temperature detecting device by heating a solid phase raw material by heating it and then solidifying it. The precision of precision ensures the reproducibility of the heat treatment state.

As a result of intensive research, the inventors have found that the above problems can be solved by introducing the concept of the deterioration state of the temperature detecting device, the setting state, and the reference temperature under the calibration method to the data of the temperature detecting device, thereby completing the present invention.

As described above, according to the present invention, there is provided a method for heat-treating a solid phase raw material, which is obtained by heating a solid phase raw material contained in a container by a heating device, and then solidifying the solid phase raw material to obtain an ingot thereof. In this method, the temperature of the solid phase raw material is detected by a temperature detecting device, and the temperature at which the solid phase raw material is fixed immediately before the completion of melting is referred to as a reference temperature Tm ° C, and temperature control is performed based on the reference temperature Tm ° C.

Moreover, according to the present invention, a method for producing an ingot in which an ingot is produced by a heat treatment method using the solid phase raw material, a method for producing a processed product obtained by processing an ingot produced by the production method, and a processed product can be provided. In particular, a method of producing a processed material derived from a tantalum material, and use thereof A method of manufacturing a solar cell of a tantalum solar cell by the processed article produced by the method.

Further, according to the present invention, it is possible to provide a heat treatment apparatus for a solid phase raw material, which is used for the heat treatment method of the solid phase raw material, and includes: a container for storing the solid phase raw material, and a temperature detecting device for detecting the temperature of the solid phase raw material. , a heating device, and a temperature detecting device that detects the temperature of the heating device.

According to the present invention, it is possible to provide a method for eliminating the deviation of the setting state, the deterioration state, the calibration method, and the like of the temperature detecting device in the heat treatment in which the solid phase raw material is heated and melted and solidified to exceed the measurement. The precision of precision ensures the reproducibility of the heat treatment state.

That is, according to the present invention, in the heat treatment of the solid phase raw material, even under conditions in which it is difficult to control the temperature, the control can be performed with high precision and good reproducibility. Therefore, by focusing on various characteristics, the cast product can be cast with good reproducibility by the required conditions.

The heat treatment method of the solid phase raw material of the present invention can further exert the above aspect when the temperature detecting device is placed in a container or at a temperature which is thermally conductive with the container and can detect a temperature associated with the temperature of the solid phase raw material. effect.

Moreover, the heat treatment method of the solid phase raw material of the present invention can further exert the above effects when the temperature control includes the following, that is, the difference between the detection temperature of the temperature detecting device and the reference temperature Tm ° C (Tm- T) When °C is set to ΔT°C, and the required set temperature difference in the heat treatment is ΔTs°C, The control set temperature Th is corrected by (ΔTs - ΔT) °C.

Further, in the heat treatment method of the solid phase raw material of the present invention, when the solid phase raw material is a brittle material for an ingot, and particularly when the brittle material is a tantalum material for a polycrystalline ingot, the above effects can be further exerted.

The above effects can be further exerted in the case where the ingot of the present invention and the processed product obtained by processing the same are brittle materials, in particular, polycrystalline ingots and processed materials derived from a tantalum material.

In the present invention, the term "processed material derived from a tantalum material" means a tantalum block and a tantalum wafer.

In addition, the term "tantal solar cell" manufactured using a processed material derived from a tantalum material refers to a "tantal solar cell" which constitutes the smallest unit, and a "tan solar cell module" which is electrically connected in plurality. "."

That is, according to the heat treatment method of the solid phase raw material of the present invention, the ingots and processed articles of the brittle material having the desired characteristics, particularly the ingot ingots, blocks and wafers, can be produced with good reproducibility. Stable solar cells with the required characteristics are stably supplied to the market.

(heat treatment method of solid phase raw materials)

The heat treatment method of the solid phase raw material of the present invention is characterized in that the solid phase raw material accommodated in the container is heated by a heating device, and the solid phase raw material is solidified to obtain the ingot, and In this method, the temperature of the solid phase raw material is detected by a temperature detecting device, and the temperature at which the solid phase raw material is fixed immediately before the completion of melting is set as the reference temperature Tm ° C, and temperature control is performed based on the reference temperature Tm ° C.

The method of determining the reference temperature Tm ° C (hereinafter sometimes "°C" is omitted) will be described using a drawing.

Fig. 1 is a conceptual diagram showing a change in temperature of a container during melting of a solid phase raw material, that is, a temperature change when a solid phase raw material in a vessel is melted and heated by a heater.

First, when heating is started, the temperature gradually rises (region I). If the inside of the container is in a mixed state of the solid phase and the liquid phase, the temperature of the melt is substantially at the melting point of the solid phase raw material before the solid phase raw material is completely melted. Become a fixed value (Zone II). The average value of the detected temperatures of the temperature detecting devices in this state is determined as "Tm". That is, the reference temperature Tm is the detected temperature of the temperature detecting device when the molten liquid in the container is the melting point of the solid phase raw material. When heating is continued thereafter, the temperature starts to rise again after all the melting, and if the heating is stopped, the temperature is lowered (region III).

The reference temperature Tm is a value that completely reflects the influence of the deviation factor of the absolute value of the detected temperature, that is, the value including all the errors.

For example, when the temperature detecting device is a thermocouple, it includes factors such as deviation of the temperature calibration method, deterioration over time caused by continued use after calibration, deviation of the set position, and deviation from contact with peripheral parts. In the thermocouple, as a method for improving the measurement accuracy, there is a method of setting a reference temperature contact (for example, setting 0 ° C in ice water as a cold junction), thereby reliably suppressing temperature deviation of the cold junction. However, it has no effect on other deviations (errors).

Moreover, when the temperature detecting device is a radiation thermometer, the deviation of the temperature calibration method, the deterioration of the detecting element over time, and the deviation of the observation point are also included. The difference, the deviation caused by the turbidity state of the window for temperature measurement, and the like.

Therefore, by controlling the heating temperature so that the reference temperature becomes a fixed value, most of the deviation factor can be eliminated. Although it is not possible to completely eliminate the deviation of the temperature calibration method or the deterioration over time caused by continued use after calibration, the measurement deviation of the temperature region close to "Tm" which is important for crystal growth can be suppressed to a considerable extent. Thereby the reproducibility of the heat treatment (casting) conditions is ensured.

Preferably, the temperature detecting device is disposed at a position of a container or a temperature that is thermally conductive with the container and can detect a temperature associated with the temperature of the solid phase material. As described below, the vicinity of the center of the lower surface of the container is optimally obtained. It is especially preferred to reflect the value of the temperature of the molten solid phase material in the vessel.

In the heat treatment method of the solid phase raw material of the present invention, the temperature control includes a case where the detection temperature of the temperature detecting device is set to T ° C, and the difference (Tm - T) ° C from the reference temperature Tm ° C is set to ΔT ° C, when the set temperature difference required for the heat treatment is ΔTs ° C, the control set temperature Th is corrected by (ΔTs - ΔT) °C. Specifically, it is described in detail in the examples.

(solid phase raw material)

In the present invention, examples of the solid phase raw material to be heat-treated include a semiconductor material such as ruthenium or iridium; a III-V compound such as gallium arsenide; a II-VI compound such as zinc selenide; and other II-IV. a compound semiconductor material such as a group V2 compound or a group I-III-VI2 compound; a metal material such as aluminum, copper, titanium, chromium or the like; an insulating material such as an oxide, a nitride or a sulfide.

Among these, in order to fully exert the effects of the present invention, brittleness is preferred. Materials, especially for enamel materials.

(heat treatment device for solid phase raw materials)

The heat treatment apparatus for a solid phase raw material of the present invention includes a container for storing a solid phase raw material, a temperature detecting device for detecting a temperature of the solid phase raw material, a heating device, and a temperature detecting device for detecting a temperature of the heating device.

The heat treatment apparatus which can be used for the heat treatment method of the solid phase raw material of the present invention is not particularly limited, and as long as the above apparatus is included, a known apparatus can be used.

For example, a device in which the molten raw material in the container is gradually solidified from the lower portion by a method in which the bottom surface of the container is cooled by a cooling mechanism such as a refrigerant circulation provided on the base side of the container; The container is moved away from the heating mechanism by a lifting drive mechanism.

In order to control the crystal growth (solidification) at the bottom of the container as accurately as possible, it is preferred to detect the temperature near the bottom of the container. In particular, it is particularly preferable that the vicinity of the center of the bottom of the container in the surface is difficult to be directly affected by a heater or the like.

It is considered that depending on the configuration of the heat treatment apparatus, there is also a case where the temperature detecting device of the container cannot be provided in the position as described above. In this case, the temperature detecting device of the container can be provided at a position that is thermally conductive with the container.

The reference temperature Tm is determined by the temperature detecting device, and the detected temperature T of the container at a certain point in time is measured. Further, if (T-Tm) is set as the corrected container detection temperature, the value of (T-Tm) at a certain time point in the heat treatment condition is the same as the previous condition (required condition). It is sufficient to change the control set temperature Th for the heater. Or you can use the heat before the previous time Temperature control is performed on the relationship between the detected temperature of the heater and the Tm investigated by the time. However, when the exchange or position change of the temperature detecting device of the container is performed, the deviation generated at this time is also included, which is not preferable.

Fig. 2 is a schematic cross-sectional view showing an example of a heat treatment apparatus to which the heat treatment method of the present invention can be applied.

The apparatus is generally used for casting a polycrystalline ingot block, and includes a chamber (closed container) 7 constituting a resistance heating furnace.

A container 1 made of graphite or quartz (SiO ₂ ) or the like is disposed inside the chamber 7, and the internal environment of the chamber 7 can be maintained in a sealed state.

A container table 3 made of graphite supporting the container 1 is disposed in the chamber 7 in which the container 1 is housed. The container table 3 can be raised and lowered by the elevation drive mechanism 12, and the refrigerant (cooling water) in the cooling tank 11 is circulated inside.

A container 2 other than graphite or the like is disposed on the upper portion of the container table 3, and the container 1 is disposed therein. Instead of the outer container 2, a cover made of graphite or the like surrounding the container 1 may be disposed.

The heater 10 such as a graphite heater is disposed so as to surround the outer container 2, and the heat insulating material 8 is disposed so as to cover it from above.

The heater 10 can be heated from the periphery of the container 1 to melt the solid phase material 4 in the container 1.

The heating means can be controlled by the heating of the heater 10, the cooling from the lower side of the container 1 by the cooling tank 11, and the raising and lowering of the container 1 by the lifting/lowering mechanism 12. The form and arrangement are not particularly limited.

In order to detect the temperature of the bottom surface of the container 1, respectively, attached to the center of the lower surface of the container 1 The thermocouple 5 is placed near the container, and the thermocouple 6 under the outer container is placed near the center of the lower surface of the outer container 2, and the temperature data is recorded by the control device 9. Further, the heater temperature is detected by the heater temperature detecting device (output control thermocouple 13), and the heating state of the heater 10 is controlled. In addition to the above thermocouples, thermocouples or radiation thermometers for detecting temperature can also be configured.

In the present invention, in the above-described container lower thermocouple 5 and outer container lower thermocouple 6, the temperature at which the solid phase raw material is fixed immediately before the completion of melting is detected, and is set as the reference temperature Tm.

The chamber 7 can maintain the inside thereof in a sealed state without flowing into the outside of oxygen, nitrogen, or the like. Usually, after the raw material such as polycrystalline germanium is introduced and before it is melted, the inside of the chamber 7 is evacuated, and then argon gas is introduced. Wait for the inert gas to keep it in an inert environment.

With such a device, the heat treatment of the polycrystalline ingot is basically carried out by filling the container 1 with the crucible as the solid phase material 4; by degassing (vacuumization) and introducing the inert gas And replacing the gas in the chamber 7; melting the solid phase raw material 4 by heating; confirming and maintaining the melting; starting the curing by the temperature control and the action of the lifting drive mechanism 12; confirming the end of the curing; and annealing and ingot removal .

The above description has been made on a heat treatment method and a device using ruthenium as a solid phase raw material, and the heat treatment method of the solid phase raw material of the present invention can also be applied to a CZ (Czochralski, Qiu) for casting of a single crystal in a different manner. The claskin method, a ribbon method in which a wafer is directly grown from a melt, and a spheroidal method in which a droplet of a molten metal is dropped by an inert gas such as argon. The heat treatment method and the heat treatment device.

(ingot)

The ingot (casting product) of the present invention is produced by a heat treatment method of the solid phase raw material of the present invention.

In the case where the solid phase raw material is a tantalum material, a tantalum ingot can be produced.

(processed product)

The processed product of the present invention can be obtained by processing an ingot.

In the case where the solid phase raw material is a tantalum material, a processed material derived from the tantalum material can be obtained.

As described above, the processed material derived from the tantalum material refers to a tantalum block and a tantalum wafer.

The crucible block can be obtained, for example, by cutting a crucible ingot of the present invention into a prismatic shape by using a known device such as a band saw.

Moreover, the surface of the block can be polished as needed.

The tantalum wafer can be obtained, for example, by processing a saw piece into a desired thickness by using a known device such as a multi-wire cutter. The current thickness is usually about 170 to 200 μm, but the current tendency is to reduce the cost and to reduce the thickness.

(矽 solar battery)

The tantalum solar cell of the present invention is produced by using the processed material (ruthenium wafer) derived from the tantalum material of the present invention.

The tantalum solar cell can be fabricated, for example, using the tantalum wafer of the present invention and by a known solar cell process. That is, using a known material and in a case where a p-type impurity-doped germanium wafer is doped by a known method, an n-type impurity is doped to form an n-type layer to form a pn junction, and a surface electricity is formed. The solar cell is obtained from the electrode and the back electrode. Similarly, in the case of a germanium wafer doped with an n-type impurity, a p-type impurity is doped to form a p-type layer to form a pn junction, and a surface electrode and a back surface electrode are formed to obtain a germanium solar cell. Alternatively, a MIS (Metal-Insulator-Semiconductor) type solar cell, such as a wafer, may be deposited by sandwiching a thin insulating layer and depositing a metal such as a pn bond. On the contrary, a thin film of a conductive amorphous type or the like is formed, and a p-type or n-type germanium heterojunction of a different structure is used. Further, a plurality of them are electrically connected to obtain a tantalum solar battery module.

As described above, in the present specification, the concept of "solar battery unit" and "solar battery module" is simply referred to as "solar battery". Therefore, if it is disclosed as "a solar cell", for example, it means "a solar cell" and "a solar cell module".

Example

Hereinafter, the present invention will be specifically described by way of Test Examples, but the present invention is not limited by the test examples.

(Test Example 1) Study on the deviation of crystal grain size of polycrystalline ingots

Using the heat treatment apparatus shown in FIG. 2, and by heat treatment of the solid phase raw material of the present invention and the prior method, heat treatment of the polycrystalline ingots was performed five times, thereby evaluating the crystal grain size (crystal nucleation generation) sensitive to temperature conditions. Deviation of density).

A container made of graphite is provided on the graphite container table 3 (880 mm × 880 mm × thickness 200 mm) in the heat treatment apparatus shown in Fig. 2 (internal container 2 Dimensions: 900 mm × 900 mm × height 460 mm, wall thickness and side wall thickness of 20 mm), and a quartz container 1 is provided therein (internal size: 830 mm × 830 mm × 420 mm, bottom plate wall thickness and The side wall thickness is 22 mm). Further, as a temperature detecting device for the container, a thermocouple (thermocouple A) 5 under the container is placed near the center of the lower surface of the container 1, and an outer container is placed at two places near the center of the lower surface of the outer container 2 (20 mm below the container). Thermocouple (thermocouple B) 6. Further, as a temperature detecting device for the heater, a thermocouple (thermocouple H) 13 for output control of the heater is provided at a position 40 mm from the heater (graphite heater) 10. The detection temperature in each thermocouple is marked with a subscript, and is set to Ta, Tb, and Th.

The temperature is controlled by the control device 9 by setting the detection temperature Th and adjusting the output of the heater 10, and the respective detection temperatures Ta, Tb, and Th are recorded every 10 seconds.

Figures 7 and 8 in Figure 2 show the chamber and the insulating material, respectively.

The 420 kg of the solid phase raw material (矽) 4 having the boron dopant concentration adjusted was placed in the container 1 so that the specific resistance of the ingot became about 2 Ωcm, and was set at a specific position in the apparatus. Then, the inside of the apparatus was evacuated and replaced with argon gas. Thereafter, the solid phase raw material 4 is melted by the heater 10, and after confirming the melting of all the raw materials, the reference temperature Tm to be immobilized immediately before the completion of the melting is measured. Here, the reference temperature Tm corresponding to the thermocouple A and the thermocouple B is denoted by a subscript, and is set to Tma and Tmb.

The temperature correction point in the heat treatment method of the solid phase raw material of the present invention is set to 30 minutes after the completion of the melting of the solid phase raw material 4, and the lowering of the vessel 1 using the elevation drive mechanism 12 including the cooling tank 11 is started. 1 hour ago.

The optimum value (°C) as the optimum temperature condition is shown in Table 1.

Here, "△Ta" means thermocouple A (detection temperature - detection temperature at the time of melting stability of solid phase raw material) Ta-Tma, and "△Tb" means thermocouple B (detection temperature - solid phase raw material) The temperature at which the melt is stable is determined by Tb-Tmb.

As is clear from Table 1, since the data of either of the thermocouple A and the thermocouple B can be used, ΔTa and ΔTb can be made to coincide within the error range, and therefore, the correction can be appropriately selected in the correction of the heating control temperature. Moreover, based on the result, it is presumed that the temperature detection device can be similarly controlled when the temperature detecting device is provided in a portion where the container 1 is thermally conductive.

Under the ideal conditions, since the set temperature difference ΔTs is -20 ° C, in the first to fifth times of the embodiment, ΔTa and ΔTb are respectively set to -20 ° C, and (ΔTs - ΔT) The correction value of the control set temperature Th is calculated, and only the subsequent heat treatment conditions are corrected by the correction value.

That is, when ΔTa and ΔTb are each -23 ° C, the set temperature is increased by 3 ° C because the set temperature difference ΔTs (-20 ° C) is lower than the ideal condition by 3 ° C. Specifically, Th was changed from 1450 ° C to 1453 ° C, and the temperature program was corrected by the correction value in the same manner.

In the first to fifth times of the prior art, as shown in Table 1, the heat treatment was carried out without the above temperature correction.

Each of the obtained ingots was machined into 25 pieces (156 mm × 156 mm × 200 mm each) using a band saw, and then sliced using a wire saw to obtain a tantalum wafer (156 mm × 156 mm × thickness 0.18 mm). ) About 12,000 pieces.

The crystal grain size evaluation is the most suitable for the 25 blocks cut out from each ingot. The wafer was carried out near the bottom, and the average of the crystal grain sizes of the 25 wafers was set as the average crystal grain size of the ingot. Further, when the crystal grain size is evaluated, it is clearly observed on the surface of the polycrystalline silicon wafer that the grain boundary is not counted as a grain boundary here.

The so-called 晶3 grain boundary, in the coincidence lattice theory, refers to the grain boundary defined by the reciprocal of the volume ratio of the unit cell of the coincident crystal lattice to the unit cell of the crystal. . Since the Σ3 grain boundary is derived from a layered defect caused by stress or the like in a crystal grain grown by a single crystal nucleus, it should not be counted as a grain boundary when evaluating the number of nucleation nuclei, so here Not counted as grain boundaries.

The crystal grain size was measured using a digital microscope (manufactured by Keynes Co., Ltd., type: VHX-1000).

The evaluation results of the obtained crystal grain size are shown in Table 2.

Table 2 shows that the average value of the five times of the examples was 100. Compared with the previous examples, the standard deviation of the fifth time of the examples was small, the average crystal grain size was uniform, the reproducibility was good, and the temperature control was good. The ground works.

Further, the obtained germanium wafer was put into a usual solar cell process, and each ingot was fabricated into 12,000 solar cells (outer shape: 156 mm × 156 mm × thickness 0.18 mm) and the output (W) thereof was measured. The average value of the output was taken in each of the ingot units, and the result of setting the average of the five times of the examples to 100 was shown in Table 2.

According to the results, the standard deviation of the fifth time of the example was small as compared with the previous example, and the deviation was small in terms of the characteristics of the solar cell. In the average output of each ingot, the measurement of the previous example can also be observed. When the value is higher than the average value of the examples, but the average value of the five times is compared, the average value of the previous example is 0.32% lower than that of the embodiment, and it is considered that the output is still lowered as a whole due to the deviation.

Moreover, the obtained solar cells of the prior art and the examples were put into a normal solar cell module process to produce a solar cell module, and as a result, similarly to the solar cell, the solar cell module of the solar cell of the example was produced. Compared with the modules of the previous examples, the group has a tendency to have a higher average output and less deviation.

As described above, the polycrystalline germanium ingot is exemplified as an example of the embodiment of the present invention, and it is also possible to control the curing of other materials with good reproducibility by using the same temperature control.

In the ductile material such as metal, since various characteristics are exhibited depending on the difference in crystal structure, the heat treatment method of the present invention can also be applied.

In the case of a brittle material, there is also a case where cracking occurs due to thermal stress inside the cast material, and in the case of a semiconductor material, crystal defects (dislocation, etc.) are introduced due to stress, thereby greatly reducing electrons. In the case of the characteristics of the device, as in the case of the ruthenium, there is a case where the crystal grain size greatly affects the characteristics, and the heat treatment method of the present invention can further exert an effect.

1‧‧‧ container

2‧‧‧ outer container

3‧‧‧ container table

4‧‧‧ Solid phase raw materials (矽)

5‧‧‧ Thermocouple under the container (thermocouple A)

6‧‧‧ Thermocouple under the outer container (20 mm thermocouple B under the container)

7‧‧‧ chamber

8‧‧‧Insulation materials

9‧‧‧Control device

10‧‧‧heater (graphite heater)

11‧‧‧Cooling trough

12‧‧‧ Lifting drive mechanism

13‧‧‧Thermal output control thermocouple

Fig. 1 is a conceptual diagram showing changes in the detection temperature of a container during melting of a solid phase raw material.

Fig. 2 is a schematic cross-sectional view showing an example of a heat treatment apparatus to which the heat treatment method of the present invention can be applied.

Claims (10)

A method for heat-treating a solid phase raw material, which is obtained by heating a solid phase raw material stored in a container by a heating device, and then solidifying the solid phase raw material to obtain an ingot thereof, and the method is The temperature detecting device detects the temperature of the solid phase raw material, sets the temperature at which the solid phase raw material is fixed immediately before the completion of melting, and sets the temperature to the reference temperature Tm ° C, and performs temperature control based on the reference temperature Tm ° C. The method for heat-treating a solid phase material according to claim 1, wherein the temperature detecting device is provided at the container or at a position having a temperature which is thermally conductive with the container and which can detect a temperature associated with the temperature of the solid phase material. The method for heat-treating a solid phase raw material according to claim 1, wherein the temperature control is performed by setting a detection temperature of the temperature detecting device to T ° C, and setting a difference (Tm - T) ° C from the reference temperature Tm ° C to ΔT. °C, when the set temperature difference required for the heat treatment is ΔTs °C, the control set temperature Th is corrected by (ΔTs - ΔT) °C. The method for heat-treating a solid phase raw material according to claim 1, wherein the solid phase raw material is a brittle material for the ingot. The method for heat-treating a solid phase material according to claim 4, wherein the brittle material is a tantalum material for a polycrystalline ingot. A method of producing an ingot, which is produced by using a heat treatment method of the solid phase raw material of claim 1. A method of manufacturing a processed article, which is manufactured by the method of claim 6 The ingot produced by the method is processed to obtain a processed product. The method of producing a processed article according to claim 7, wherein the processed material is derived from a processed material of a tantalum material. A method of producing a solar cell, which is obtained by using a processed article produced by the manufacturing method of claim 8. A heat treatment device for a solid phase raw material, which is used for a heat treatment device for a heat treatment method of a solid phase raw material according to claim 1, and the device comprises: a container for storing a solid phase raw material, and a temperature detecting device for detecting a temperature of the solid phase raw material , a heating device, and a temperature detecting device that detects the temperature of the heating device.