JP2012052235A - Manufacturing method of tantalum tube and pit carbon core, tantalum tube and pit carbon core, manufacturing method of tantalum carbide wiring, and tantalum carbide wiring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method which enables the solid-phase diffusion joining of tantalum of a prescribed shape and carbon by a simple method, and forms a carbide on a tantalum surface other than a place where the solid-phase diffusion joining of the tantalum and the carbon is performed.SOLUTION: Tantalum or a tantalum alloy is formed into a tube shape, carbon powder is press-inserted into the tube, after that, the tube is placed in a vacuum heat treatment furnace after the tube is formed into a coil shape, TaOwhich is a natural oxide membrane formed at the tantalum or on the surface of the tantalum alloy is removed, after that, the tantalum or the inside of the tantalum alloy tube and the carbon powder PIT are molecular-joined by solid-phase diffusion coupling, the carbon is intruded into the external surface of the tantalum or the tantalum alloy tube by introducing a carbon source into the vacuum heat treatment furnace, and TaC is formed.

Description

  The present invention relates to a manufacturing method of a tantalum tube and a PIT carbon core, a tantalum tube and a PIT carbon core, a manufacturing method of a tantalum carbide wiring, and a tantalum carbide wiring.

  Although there is no report yet on solid phase diffusion bonding of tantalum and carbon, Ta, Ta alloy and graphite are not recognized as a combination that can be bonded as a diffusion bonding metal on the Kobe Steel Website KOBELCO. FIG. 12 shows a combination possible diagram of metals that can be diffusion bonded, quoted from the KOBELCO website. A tantalum carbide, such as TaC, has the highest melting point among transition metal carbides, has high chemical stability, and has been reported to be researched. FIG. 13 shows a phase diagram of TaC. Conventionally, such TaC has been sought for application to various uses in a high-temperature atmosphere, and production methods by various methods as described below have been reported. The following is mentioned as a literature example of the method of manufacturing the conventional TaC.

  For example, in Patent Document 1, fine TaC powder and fine powder of other compounds such as HfC, ZrC, and HfN are mixed, sintered at 2000 ° C. in a vacuum of about 1 Pa, TaC and these other A method for producing a dense TaC sintered body by forming a solid solution of a compound and suppressing grain growth of TaC is described.

In Patent Document 2, tantalum oxide (Ta ₂ O ₅ ) and carbon are mixed, primary carbonization is performed at a predetermined temperature in a hydrogen furnace, the amount of free carbon in the obtained carbide is measured, and then this measurement is performed. A method is described in which the amount of carbon is adjusted based on the result and added to the primary carbide, followed by secondary carbonization at a predetermined temperature in a vacuum carbonization furnace to produce TaC.

In Patent Document 3, metal Ta is evaporated in a vacuum, C ₂ H ₂ gas is introduced at the same time, and the pressure during deposition / film formation rate is 6.0 × 10 6 by reactive ion plating. ^{-2 It} has excellent heat resistance with a composition ratio of 1 <C / Ta <1.2 on the surface of tungsten electron emission material by reacting at Pa · min / μm or more, and radiation current can be obtained stably even in a bad vacuum condition. In addition, a method for coating a long-life TaC film is described.

  Further, in Patent Document 4, the following (a) chromium oxide is used in a range of 50 to 99 as a release film to be coated on a mold surface used when press-molding a high-precision glass optical element such as a lens or a prism. A ceramic material comprising 1 mol% and 1 to 50 mol% of tantalum oxide, (b) a ceramic material comprising 50 to 99 mol% of chromium nitride and 1 to 50 mol% of tantalum nitride, and (c) 50 of chromium carbide. A material composed of one kind selected from ceramic materials consisting of ˜99 mol% and tantalum carbide of 1 to 50 mol% is described.

  Further, Patent Document 5 discloses a carbon composite material for a reducing atmosphere furnace that exhibits an excellent reducing gas reaction suppressing effect even in a high temperature reducing gas atmosphere exceeding 1000 ° C. and can greatly extend the product life. Describes a tantalum carbide film formed on the surface of a graphite substrate by an arc ion plating (AIP) reactive vapor deposition method using metal tantalum and a reactive gas.

  Patent Document 6 describes a method for forming a conductive Ta-based film by a CVD method using a conductive Ta-based film forming material containing a compound containing Ta and a hydrocarbon-based solvent. Yes.

  In Patent Document 7, a Ta plate is disposed on the inner wall of a graphite crucible. Then, the Ta plate is covered with carbon powder so as to come into contact with the Ta plate. Thereafter, a method is described in which the graphite crucible is heated to carbonize the Ta plate, and the inner wall of the graphite crucible is coated with TaC.

In Patent Document 8, a carbon source is applied to the surface of Ta or Ta alloy in a vacuum furnace heated to 1300 ° C. to 1600 ° C. to form a TaC and Ta ₂ C film, and then unreacted adhered to the surface. A method is described in which TaC is formed by performing high temperature annealing and heating in a vacuum so that the carbon atoms in the Ta base material diffuse into the Ta substrate.

JP-A-6-87656 JP 2000-44222 A JP-A-8-64110 JP 7-330351 A Japanese Patent Laid-Open No. 10-245285 JP 2000-265274 A JP-A-11-116399 US Pat. No. 5,383,981

  However, the one described in Patent Document 1 is a mixture of fine TaC powder and fine powder of other compounds such as HfC, ZrC, HfN, etc., and sintered at 2000 ° C. in a vacuum of about 1 Pa to obtain TaC. In order to produce, there exists a problem that formation of TaC of arbitrary shapes is difficult.

Also, those described in Patent Document 2, a mixture of a Ta ₂ O ₅ and C, after molding, because it forms a TaC through twice carbonization, similar to those of the aforementioned Patent Document 1 There is a problem that it is difficult to form TaC having a predetermined shape.

  Moreover, since the thing of patent document 3 forms the TaC film in the outer peripheral surface of a tungsten filament, and the interface with base materials, such as tungsten, is necessarily formed, the crack of TaC It is difficult to avoid the occurrence of peeling.

  Moreover, the thing of patent document 4 is formed as a film on the base-material surface similarly to the thing of patent document 3, and 50% of chromium oxide formed on the surface is made like patent document 3. It is difficult to avoid cracks, exfoliation and the like of a ceramic material or the like composed of ˜99 mol% and tantalum oxide of 1 to 50 mol%.

  In addition, the one described in Patent Document 5 is the same as that described in Patent Documents 3 and 4 because TaC is formed on the surface of a graphite material as a base material by an arc ion plating type reactive vapor deposition method. In addition, the interface between the substrate and TaC is clearly formed, and it is difficult to avoid TaC cracks, peeling, and the like.

  Moreover, since the thing of patent document 6 also forms the electroconductive Ta-type film | membrane by CVD method, similarly to the thing of the above-mentioned patent documents 3-5, a base material, an electroconductive Ta-type film | membrane, Therefore, it is difficult to avoid cracking, peeling, etc. of the conductive Ta-based film due to thermal history or the like.

  Moreover, the thing of patent document 7 forms TaC on the surface of Ta by making Ta and carbon powder contact directly, and heat-processing, although there is no description in particular in specification, Ta It is considered that the boundary between TaC and TaC appears clearly. For this reason, it is considered that the TaC layer portion is peeled off due to the thermal history.

In addition, as described in FIG. 5A to FIG. 5F of the patent document 8, the unreacted carbon atoms on the surface are diffused into the Ta substrate by high-temperature annealing after the formation of Ta ₂ C and TaC layers as shown in FIG. As a result, the Ta ₂ C layer disappears, and a TaC bulk crystal having a thickness about twice that before annealing is formed. The boundary between the Ta substrate and TaC is clearly separated by observing the enlarged photograph. For this reason, although not described in the specification, delamination between layers and cracks in the TaC layer occur due to repeated thermal stress. It is thought that it is easy to do.

Even if carbon atoms are reacted with the natural oxide film Ta ₂ O ₅ on the surface of the Ta substrate at a low temperature of 1300 ° C. to 1600 ° C., the natural oxide film Ta ₂ O ₅ is chemically stable, and the carbonization rate of Ta is low. Since the diffusion depth is very shallow, a desired thickness cannot be obtained even when a TaC film is grown by diffusing carbon atoms by performing vacuum heating annealing for several tens of hours. Combined with the heating for a long period of time, the crystal grains grow and become bulky, and the grain boundary also grows. The boundary between the Ta substrate and TaC is clearly separated, causing delamination between layers and cracks in the TaC layer. It is thought to occur easily.

  The present invention has been made in view of the above-mentioned problems, and it is possible to perform solid phase diffusion bonding of tantalum or a tantalum alloy and carbon by a simple method, and a place for solid phase diffusion bonding of tantalum or a tantalum alloy and carbon. A tantalum tube that can form tantalum carbide on the tantalum surface at the same time as solid-phase diffusion bonding that can be formed on tantalum or tantalum alloys other than tantalum or tantalum carbide, and that does not peel off due to thermal history An object of the present invention is to provide a method for producing a PIT carbon core, a tantalum tube and a PIT carbon core, a method for producing a tantalum carbide wiring, and a tantalum carbide wiring.

  In order to achieve the above object, the present invention mainly has several features as follows. In the present invention, the following main features are provided singly or appropriately combined.

In the present invention, while tantalum or a tantalum alloy is processed into a tube shape, carbon powder is press-fitted into the tube by a PIT method, and the tantalum or tantalum alloy tube is rolled and formed, while the workability before solidification is high. After processing the whole into a predetermined coil shape, it is installed in a vacuum heat treatment furnace, and heat treatment is performed under the condition that Ta ₂ O ₅ which is a natural oxide film formed on the tantalum or tantalum alloy surface is sublimated, After removing Ta ₂ O ₅ , a carbon source is introduced into the vacuum heat treatment furnace to further increase the temperature in the vacuum heat treatment furnace, and solid phase diffusion of the inner surface of the tantalum or tantalum alloy tube and the carbon powder PIT is performed. The carbon powder compressed and pressure-bonded to the tantalum or tantalum alloy surface by the PIT method is sintered and solidified at a high temperature under the temperature condition for molecular bonding by bonding. Provided is a method for producing a tantalum tube and a PIT carbon core, which is TaC formed by solid-phase diffusion molecular bonding with the inner surface of the tube and carbon entering the outer surface of the tantalum or tantalum alloy tube. .

In the present invention, tantalum or a tantalum alloy is processed into a tube shape, carbon powder is press-fitted into the tube by a PIT method, and the tantalum or tantalum alloy tube is rolled and formed into a ribbon shape before being sintered and solidified. After the whole is processed into a predetermined coil shape while the workability is high, it is placed in a vacuum heat treatment furnace, and the condition that Ta ₂ O ₅ which is a natural oxide film formed on the tantalum or tantalum alloy surface is sublimated After the heat treatment is performed and the Ta ₂ O ₅ is removed, a carbon source is introduced into the vacuum heat treatment furnace to further increase the temperature in the vacuum heat treatment furnace, and the inner surface of the tantalum or tantalum alloy ribbon and the Charcoal compressed and pressure welded by the PIT method with the inner surface of the tantalum or tantalum alloy ribbon under temperature conditions for molecular bonding of carbon powder PIT by solid phase diffusion bonding A tantalum tube characterized in that the elementary powder is TaC formed by sintering and solidifying at a high temperature and solid-phase diffusion molecular bonding with the inner surface of the ribbon and simultaneously carbon entering the outer surface of the tantalum or tantalum alloy ribbon; A method for producing a PIT carbon core is provided.

  The present invention provides a tantalum tube and a PIT carbon core manufactured by the above-described manufacturing method, wherein the tantalum tube and the PIT carbon core are tantalum carbide filaments or heaters.

The present invention creates a carbon-rich substrate surface by patterning with a laser or an electron beam into a predetermined shape under vacuum on a SiC semiconductor substrate to form a carbon-rich substrate surface, and patterning the tantalum or tantalum alloy on the portion, The Ta ₂ O ₅ , which is a natural oxide film formed on the surface of the tantalum or tantalum alloy, was subjected to heat treatment under the condition of sublimation, and the Ta ₂ O ₅ was removed from the surface of the patterned tantalum or tantalum alloy. A method of manufacturing a SiC semiconductor tantalum carbide wiring formed by introducing carbon from the surface of the patterned tantalum or tantalum alloy and the carbon-rich portion of the SiC substrate surface after introducing a carbon source and providing heat treatment is provided. To do.

The present invention is a natural oxide film formed on a surface by patterning tantalum or a tantalum alloy on the substrate surface by creating a carbon-rich SiC substrate surface environment by heat-treating the SiC semiconductor substrate under vacuum. A heat treatment is performed under conditions in which Ta ₂ O ₅ is sublimated, the Ta ₂ O ₅ is removed from the surface of the patterned tantalum or tantalum alloy, a carbon source is introduced, and a heat treatment is performed. Alternatively, a method for producing a tantalum carbide wiring of an SiC semiconductor formed by infiltrating carbon from a carbon-rich SiC surface portion of a tantalum alloy surface and an SiC substrate surface is provided.

  The present invention is a tantalum carbide wiring manufactured by the above-described manufacturing method, wherein the tantalum carbide wiring is formed by carbon intrusion into all surfaces of tantalum or a tantalum alloy that are CVD-processed or vacuum-deposited into a predetermined shape. A tantalum carbide wiring that is TaC is provided.

  According to the present invention, a tantalum-carbon bond having a predetermined shape can be formed by a simple method, and there is no occurrence of cracking, peeling, or the like of the tantalum-carbon bond. For example, the superior high melting point, high hardness, mechanical properties, electrical properties, etc. possessed by TaC can be reliably exhibited, and can be easily applied to various applications.

The schematic diagram of the vacuum heating furnace used for the manufacturing method of the tantalum and carbon combination thing concerning the embodiment of the present invention. The conceptual diagram which shows the increase process of the joining area of the diffusion joining part of Ta and a graphite in the solid phase diffusion joining process which concerns on embodiment of this invention. The arrangement plan of the material which joins Ta and graphite concerning the embodiment of the present invention is shown. The gradient composition cross-sectional enlarged photograph of the tantalum carbide of the joining part carburized layer of the sample which made the solid phase diffusion bond of the graphite and tantalum which concern on embodiment of this invention. The conceptual diagram of the process flowchart which makes a carbon source introduce | transduce after making the oxide film of the surface of the tantalum which concerns on embodiment of this invention detach | leave, and carburizes to Ta surface, and makes tantalum carbide. The conceptual diagram which shows the heating conditions of the vacuum heating furnace which shows the vacuum heating temperature control of the process of the said FIG. 5 which concerns on embodiment of this invention, and the detachment | desorption time of a natural oxide film. Sectional enlarged photograph _{Ta 2 C · Ta 4 C 3} · TaC is formed on the substrate surface carburization to tantalum substrate surface according to an embodiment of the present invention. The conceptual diagram which shows an example of the manufacturing process of the PIT system carbon inner core tantalum tube which concerns on embodiment of this invention. The conceptual diagram which shows an example of sectional drawing of the PIT system carbon core tantalum tube concerning embodiment of this invention It is a figure which shows the flowchart which manufactures the carbide electrode of the tantalum which concerns on embodiment of this invention. It is a figure which shows the flowchart which manufactures the tantalum carbide wiring which concerns on embodiment of this invention. Figure of possible combinations of metals that can be diffusion bonded quoted from the KOBELCO website. The figure which shows the phase diagram of Ta and C.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a view showing an outline of a vacuum heating furnace used in a method for producing tantalum and a carbon bond according to an embodiment of the present invention. In FIG. 1, reference numeral 1 is a vacuum heat treatment furnace such as a vacuum heating furnace, 2 is a vacuum chamber, 3 is a preheating chamber, 4 is a transfer chamber, 5 is a base plate of tantalum or tantalum alloy, 6 is a preheating lamp, and 8 is a support. , 9 is a transport tray, 10 is a lift, 11a is a carbon tray that also serves as a heat protection member, 11b is a heat protection member, 12 is a heat reflecting plate, 13 is a carbon source inlet, 14 is a vacuum pump connection port, 15 Is an inlet / outlet of the substrate 5, 16 is a temperature measurement window, 17 is an infrared radiation thermometer, 20 is a carbon heater, and 22 is a seal member for sealing the space 2 between the transfer chamber 4 and the vacuum chamber.

  FIG. 2 shows a process of increasing the bonding area of tantalum and graphite diffusion bonding parts in the solid phase diffusion bonding process according to the present embodiment. In diffusion bonding, it is considered that the process proceeds as shown in FIG. FIG. 2A shows a state in which the joint surfaces are abutted at room temperature. Due to the heating and pressurizing, the contact protrusions are deformed by the plastic deformation and creep deformation mechanisms, and the contact area increases. In parallel with this, bonding proceeds by the diffusion of atoms to the surface of the non-adhered portion (void) (FIG. 2B). In FIG. 2 (c), the role of diffusion becomes more important, and the disappearance of voids and the movement of some joint boundaries occur. When the bonding further proceeds, as shown in FIG. 2D, voids left in the crystal grain boundaries disappear due to the diffusion of atoms. However, each of these stages proceeds in an overlapping manner.

As shown in FIG. 3, an embodiment will be described in which a graphite block or a graphite sheet and Ta are set in a high-temperature high-vacuum heat treatment furnace, and bonding is performed by annealing in a high-vacuum environment. As experimental conditions, vacuum annealing was performed at 2000 ° C. to 2200 ° C. (1 × 10 ⁻⁵ torr) for 2 to 10 hours.
I. A graphite block or graphite sheet and Ta are placed in the preheating furnace in the high-temperature high-vacuum heat treatment furnace in the arrangement as shown in FIG. 3, and the inside of the furnace is evacuated to about 1 × 10 ⁻⁵ torr.
II. When the inside of the preheating furnace is evacuated, the sample is heated slowly in vacuum until the sample temperature reaches 800 ° C., and the gas in the furnace is discharged.
III. By carrying the sample from the preheating furnace to the heat treatment furnace, the temperature is instantaneously increased from 800 ° C. to 2000 ° C. to 2200 ° C., and vacuum annealing is performed for 2 to 10 hours.

FIG. 4 shows an enlarged photograph of the gradient composition cross section of tantalum carbide in the joint carburized layer of the sample obtained by solid phase diffusion bonding of graphite and tantalum performed in the above process. Carbon diffuses inward from the surface of Ta, and a substantially uniform TaC layer is formed on the surface layer. On the inner surface of the TaC layer, Ta ₄ C ₃ , Ta as an anchor layer (transition layer) for bonding Ta and TaC. ₂ C layer appears. The enlarged cross-sectional view of the bonded portion in FIG. 4 confirms that the carbon and tantalum metal are molecularly diffusion bonded through the anchor layer (transition layer).

The flowchart shown in FIG. 5 illustrates the carburizing process according to the present embodiment. Carburizing treatment is performed by directly irradiating the metal Ta with carbon vapor pressure in a vacuum environment, and then high-vacuum annealing is performed to enter the bulk. The carbon concentration in the layer is made uniform by promoting the diffusion of carbon atoms. TaC is synthesized by inserting metal Ta into a high-temperature vacuum carbonization furnace and directly irradiating the metal Ta with carbon vapor pressure from a carbon heater in a vacuum environment to cause carbonization reaction. As experimental conditions, carburizing treatment is performed at 1700 ° C. to 2250 ° C. (1 × 10 ⁻³ torr) for 2 hours.

FIG. 6 shows a temperature profile during the process of FIG. A preferable heat treatment condition for sublimation of Ta ₂ O _5, which is a natural oxide film, can be performed at a relatively low temperature if the processing pressure is low. In order to reliably sublimate the natural oxide film on the surface, the pressure is about 1 Pa. In the following, it is preferable to perform heat treatment under conditions in the range of about 1750 ° C. to 2250 ° C., more preferably in the range of about 1860 ° C. to 2500 ° C. at a pressure of about 0.5 Pa or less. By performing the heat treatment under such conditions, Ta ₂ O ₅ which is a natural oxide film formed on the surface is surely sublimated and removed.

After removing Ta ₂ O ₅ which is a natural oxide film, a preferable heat treatment condition for introducing a carbon source into the vacuum heat treatment furnace 1 to form tantalum carbide on the surface of the tantalum or tantalum alloy substrate 5 is pressure. It is a range of about 1860 ° C. or more and 2500 ° C. or less at about 1 Pa or less. More preferably, it is in the range of about 2000 ° C. to 2500 ° C. at a pressure of about 0.5 Pa or less.

When a graphite resistance heater is used as the heater under the heat treatment conditions after the removal of Ta ₂ O ₅ , which is a natural oxide film, steam from the heater can serve as a carbon source. However, under the tantalum carbide manufacturing conditions according to the present embodiment, the graphite heater is also consumed heavily. Thus, immediately after the output of the radiation thermometer changes, a carbon material as a carbon source is separately used. It is preferable to install in the heat treatment chamber together with the material 5. A gas containing carbon can also be introduced.

FIG. 7 shows an enlarged cross-sectional photograph in which Ta ₂ C, Ta ₄ C ₃ and TaC are formed on the Ta substrate surface by carburizing on the tantalum substrate surface. Carbon diffuses from the Ta surface to the surface layer. A substantially uniform TaC layer is formed. On the inner surface of the TaC layer, Ta ₄ C ₃ and Ta ₂ C layers appear as anchor layers (transition layers) for bonding Ta and TaC. The enlarged sectional view of the surface of the tantalum substrate in FIG. 7 confirms that tantalum carbide and tantalum metal are molecularly bonded via an anchor layer (transition layer).

  FIG. 8 shows an example of the manufacturing process of the PIT-type carbon inner core tantalum tube. Tantalum metal is processed into a tube shape, carbon powder or petroleum coke powder is injected, rolled, drawn, and drawn to form a round or ribbon-shaped wire tube. After the oxide film on the surface of the tantalum tube is sublimated and removed by high-temperature vacuum heating, a carbon source is inserted and heated at high temperature under vacuum, so that the inner surface of the tantalum tube is solid-phase diffusion bonded with the sintered solidified carbon core. Carburized and modified to TaC, and the outer surface of the tantalum tube was carburized by inserting a carbon source to be modified to TaC, and both the inner and outer surfaces of the tantalum tube were modified to TaC. A TaC-coated carbon heater is obtained.

  FIG. 9 shows an example of a cross-sectional view of the PIT-type carbon inner core tantalum tube. Carbon heaters have traditionally been used for incandescent bulb heaters and have many advantages. However, carbon heaters that have TaC tubes coated with TaC tubes have characteristics that are very stable in terms of life and strength. The inner core can be expected to be used as a heater material for high-purity high-temperature applications.

  FIG. 10 is a view showing a flowchart for manufacturing a tantalum tube and a PIT carbon core according to an embodiment of the present invention. After the carbon powder is press-fitted into the Ta tube and the tube is rolled and formed into a coil shape, the Ta tube is heated at high temperature under vacuum to sublimate the oxide film on the surface of the Ta tube. Further, the inner core carbon powder is sintered and solidified by raising the temperature and solid-phase diffusion-bonded with the inner surface of the Ta tube to be modified to TaC. The outer surface of the Ta tube is modified to TaC by inserting a carbon source and carburizing during high-temperature vacuum heating. The process conceptual diagram which coat | covers and seals an inner core carbon heater with TaC in the above process is shown, and after processing into the predetermined shape in the PIT stage of Ta or Ta alloy which is comparatively easy to process, it concerns on this embodiment When processed under the conditions of the method for producing tantalum carbide, TaC having a predetermined shape can be formed. For this reason, it becomes possible to process and use it as an arbitrary shape also as an electrode of a filament or a heater.

  FIG. 11 is a diagram showing a flowchart for manufacturing the tantalum carbide wiring according to the embodiment of the present invention. When a carbide layer having a predetermined pattern shape is formed on the surface of the semiconductor substrate by laser irradiation or the like and tantalum or a tantalum alloy is processed under the conditions of the tantalum carbide manufacturing method according to the present embodiment, TaC patterned into the predetermined shape is formed. Can be formed. A surface of a semiconductor substrate such as silicon carbide (hereinafter referred to as SiC) is locally heated by laser irradiation or the like to form a carbonized layer having a predetermined pattern shape. Further, tantalum or a tantalum alloy is stacked on the carbonized layer formed on the semiconductor substrate by any method such as vapor deposition (Ta metal patterning step). A carbon source is introduced into a high-temperature vacuum heating furnace to perform heat treatment, and carbon is carburized from the surface of the patterned tantalum or tantalum alloy to form TaC. From the interface between the tantalum or tantalum alloy and the SiC substrate, the SiC substrate surface The carbonized SiC is solid phase diffusion bonded to tantalum or a tantalum alloy, and the tantalum or tantalum alloy is modified to TaC from the back surface to form a tantalum carbide wiring.

As described above, the method for manufacturing a tantalum carbide according to the present embodiment sublimates Ta ₂ O ₅ which is a natural oxide film formed on the surface of Ta or Ta alloy substrate in a vacuum of 1750 ° C. or higher and 2250 ° C. or lower. Then, a carbon source is introduced into the vacuum to form TaC, Ta ₄ C ₃ and Ta ₂ C on the surface of the Ta or Ta alloy substrate.

The chemical change when the natural oxide film is removed from the surface of the Ta substrate of the present invention and the carbon source is inserted into the vacuum heating furnace will be described by the following chemical formula.

Incidentally, in the conventional manufacturing method described in Patent Document 8, after a carbon source is introduced into a vacuum at 1300 ° C. to 1600 ° C. to form TaC and Ta ₂ C, it takes a long time of about 15 hours in a vacuum at 1300 ° C. to 1600 ° C. The TaC layer is grown by diffusing unreacted carbon atoms adhering to the surface by annealing.

The chemical change of the conventional manufacturing method described in Patent Document 8 is explained by the following chemical formula.

Therefore, as can be seen from the observation of the enlarged photograph published in Patent Document 8, the boundary between the Ta base material and TaC is clearly separated, and the delamination between layers and the crack of the TaC layer occur due to repeated thermal stress. It is considered easy. Even if carbon atoms are reacted with the natural oxide film Ta ₂ O ₅ on the surface of the Ta substrate at a low temperature of 1300 ° C. to 1600 ° C., the natural oxide film Ta ₂ O ₅ is chemically stable, and the carbonization rate of Ta is low. Since the diffusion depth is very shallow, a desired thickness cannot be obtained even when a TaC film is grown by diffusing carbon atoms by performing vacuum heating annealing for several tens of hours. Combined with the heating for a long period of time, the crystal grains grow and become bulky, and the grain boundary also grows. The boundary between the Ta substrate and TaC is clearly separated, causing delamination between layers and cracks in the TaC layer. It is thought to occur easily.

  In addition, although this invention is described in said preferable embodiment, this invention is not restrict | limited only to it. It will be understood that various other embodiments may be made without departing from the spirit and scope of the invention.

  According to the present invention, it is possible to reliably produce a tantalum and carbon bond by a simple method, not to mention a jig for heat treatment utilizing its excellent chemical characteristics, It has applicability to various industrial uses such as electrodes used as heaters and wiring of circuits on semiconductor wafers.

Claims (6)

Tantalum or tantalum alloy is processed into a tube shape, carbon powder is press-fitted into the tube by the PIT method, and the tantalum or tantalum alloy tube is rolled to form the whole during high workability before sintering solidification. After processing into a predetermined coil shape, it is placed in a vacuum heat treatment furnace, and heat treatment is performed under conditions where Ta ₂ O ₅ , which is a natural oxide film formed on the tantalum or tantalum alloy surface, is sublimated, and the Ta ₂ After removing O ₅ , a carbon source is introduced into the vacuum heat treatment furnace to further raise the temperature in the vacuum heat treatment furnace, and the inner surface of the tantalum or tantalum alloy tube and the carbon powder PIT are molecularly bonded by solid phase diffusion bonding. The carbon powder compressed and pressure-bonded to the tantalum or tantalum alloy surface by the PIT method is sintered and solidified at a high temperature under the temperature condition for joining. A method for producing a tantalum tube and a PIT carbon core, characterized in that it is TaC formed by solid-phase diffusion molecular bonding with the inner surface of the tantalum and simultaneously carbon entering the outer surface of the tantalum or tantalum alloy tube. Tantalum or tantalum alloy is processed into a tube shape, carbon powder is press-fitted into the tube by the PIT method, and the tantalum or tantalum alloy tube is rolled and formed into a ribbon shape and processed before solidification. After the whole is processed into a predetermined coil shape while the temperature is high, it is installed in a vacuum heat treatment furnace, and heat treatment is performed under the condition that Ta ₂ O ₅ which is a natural oxide film formed on the surface of the tantalum or tantalum alloy is sublimated. After removing Ta ₂ O ₅ , a carbon source is introduced into the vacuum heat treatment furnace to further raise the temperature in the vacuum heat treatment furnace, and the inner surface of the tantalum or tantalum alloy ribbon and the carbon powder PIT Carbon powder compressed and pressure welded to the inner surface of the tantalum or tantalum alloy ribbon by the PIT method under the temperature condition for molecular bonding by solid phase diffusion bonding A tantalum tube and a PIT carbon core characterized by being TaC formed by sintering and solidifying at a high temperature and solid-phase diffusion molecular bonding with the inner surface of the ribbon and at the same time carbon entering the outer surface of the tantalum or tantalum alloy ribbon. Manufacturing method.   A tantalum tube and a PIT carbon core manufactured by the manufacturing method according to claim 1 or 2, wherein the tantalum tube and the PIT carbon core are a tantalum carbide filament or a heater. core. A carbon-rich substrate surface is formed by patterning with a laser or an electron beam into a predetermined shape under vacuum on a SiC semiconductor substrate to form a carbon-rich substrate surface, and tantalum or a tantalum alloy is patterned on the portion, and the patterned tantalum or A heat treatment is performed under the condition that Ta ₂ O ₅ , which is a natural oxide film formed on the surface of the tantalum alloy, is sublimated, and after removing the Ta ₂ O ₅ from the surface of the patterned tantalum or tantalum alloy, carbon A method for producing a tantalum carbide wiring of an SiC semiconductor formed by introducing heat from a carbon-rich portion of the surface of the patterned tantalum or tantalum alloy and the surface of the SiC substrate and introducing a heat treatment. The SiC semiconductor substrate is heated under vacuum to create a carbon-rich SiC substrate surface environment, and tantalum or a tantalum alloy is patterned on the substrate surface, and Ta ₂ O, which is a natural oxide film formed on the surface. ₅ is subjected to a heat treatment under the condition of sublimation, and after removing Ta ₂ O ₅ from the surface of the patterned tantalum or tantalum alloy, a carbon source is introduced to perform the heat treatment, and the patterned tantalum or tantalum alloy Of SiC semiconductor tantalum carbide wiring formed by carbon intrusion from a carbon-rich SiC surface portion of the surface of the substrate and the SiC substrate surface.   6. The tantalum carbide wiring manufactured by the manufacturing method according to claim 4 or 5, wherein the tantalum carbide wiring has carbon infiltrated into all surfaces of tantalum or tantalum alloy that are CVD-processed or vacuum-deposited into a predetermined shape. A tantalum carbide wiring, characterized in that the tantalum carbide wiring is made of TaC.