CN103060744B - Preparation method of combination type crucible utilized at ultra-high temperature - Google Patents
Preparation method of combination type crucible utilized at ultra-high temperature Download PDFInfo
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- CN103060744B CN103060744B CN201310045352.4A CN201310045352A CN103060744B CN 103060744 B CN103060744 B CN 103060744B CN 201310045352 A CN201310045352 A CN 201310045352A CN 103060744 B CN103060744 B CN 103060744B
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Abstract
The invention relates to a preparation method of a crucible utilized in a crystal growth process, and particularly relates to a preparation method of a combination type crucible utilized at ultra-high temperature. The method is performed according to the following steps of: (1) pretreating a tantalum crucible; (B) assembling a crucible assembly; (C) charging and carburizing; (D) removing a carbon-based material; (E) carrying out annealing heat treatment; and (F) cleaning and drying to prepare a tantalum carbide-tantalum-tantalum carbide three-layer combination type crucible. By adopting the method, the tantalum crucible is directly changed into the tantalum carbide-tantalum-tantalum carbide three-layer combination type crucible; the carburizing degree difference generated due to nonuniform temperature in the process of changing the tantalum crucible into the tantalum carbide-tantalum-carbonization candid three-layer combination type crucible is eliminated through the annealing heat treatment process, and the internal stress of a crucible body is eliminated. The combination type crucible reserves the characteristic of high strength and difficulty to crush of tantalum and has the high-temperature corrosion resistance ability of tantalum carbide, and is suitable for a high-temperature high-corrosion crystal growth or high-purity ceramic sintering environment.
Description
Technical field
The preparation method of the crucible that the present invention relates to use in monocrystalline growing process, the preparation method of the compound crucible particularly using under a kind of ultra high temp.
Background technology
Aluminium nitride (AlN) monocrystal material is the highly desirable substrate material of a kind of development of new HIGH-POWERED MICROWAVES device and short-wavelength light electrical part, but is also difficult at present obtain AlN body monocrystal material.AlN Theoretical Calculation fusing point is 2800 DEG C, and dissociation pressure is 20MPa, is therefore difficult to carry out growing single-crystal as Si melt vertical pulling method or the temperature gradient solidification law technology of adopting the same as GaAs.One of method more likely is PVT(Physical Vapor Transport at present, physical vapor transport) method.The PVT method growing principle of AlN is to be distilled and decompose at high temperature source region place by high-purity AlN powder, and by the transport of substances process in growth chamber, at low temperature seed crystal, condense in place, and then forms the process of growth of monocrystalline.Adopt PVT legal system for there being many technological difficulties in AlN monocrystalline.Wherein, selecting high-temperature stable, densification, durable, suitable crucible material is one of important topic of AlN crystal technique.The growth temperature of AlN very high (2100～2300 DEG C), and there is the Al steam of highly corrosive.General crucible and lagging material may react (such as nitrogen and AlN powder) with source material, also may introduce impurity to crystal from crucible or lagging material simultaneously, form growth defect.Therefore, the selection of crucible material is quite important, need to have following characteristics: 1, material melting point must be higher than 2500 DEG C; 2, can not form Al, N, the C eutectic of low melting point; 3, should not react with Al steam or nitrogen; 4, vapour pressure should be far below the Al of AlN and nitrogen vapour pressure; 5, long as far as possible work-ing life.
Tantalum is rare refractory metal, 2996 DEG C of fusing points, thermal conductivity 54W/ (MK) (25 DEG C), linear expansivity 6.5 × 10
-6(0 ~ 100 DEG C).The toughness of tantalum is strong, has good ductility, is difficult for broken.Tantalum, mainly as heat-resistant high-strength material, in vacuum high temperature furnace, can be used as Holder Fasteners, thermoshield, well heater and radiator element etc.Tantalum at high temperature will react with nitrogen and generate tantalum nitride, will generate low melting point eutectic with Al steam reaction, cause surface crack, after once or for several times using, can cause tantalum crucible to ftracture and scrap.
Carbonization is smooth very high chemical stability and good high-temperature behavior, 3875 DEG C of fusing points, and 5500 DEG C of boiling points, can resistance to 3800 DEG C of following high temperature.High temperature does not react with nitrogen substantially.Hardness can with the mutually handsome U.S. of diamond.And inhibiting grain growth is had to positive effect.But the smooth material fragility of carbonization is large, under the impact of high low temperature, very easily ftracture.
Smooth both performance advantage of tantalum and carbonization will be made full use of by tantalum and the smooth compound crucible forming of carbonization, can overcome again both shortcomings in application aspect, therefore, can be the grow crucible of required high-adaptability of research and development AlN crystal, to meet the requirement of physical vapor transport growing crystal material (especially for aluminum nitride crystal) to ultrahigh-temperature tolerance crucible.
Summary of the invention
The object of the invention is in order to meet the requirement of physical vapor transport growing crystal material (especially for aluminum nitride crystal) to ultrahigh-temperature tolerance crucible, provide especially a kind of tantalum crucible to obtain the preparation method of the smooth three layers of compound crucible of tantalum carbide-tantalum-carbonization by two step sintering procedures, the existing good intensity of this compound crucible, anti-high and low-temp impacts, should not ftracture, there is again the resistance to corrosion to high temperature Al steam, nitrogen or other atmosphere, become AlN or other crystal ultrahigh-temperature applicable crucible of growing.
In order to achieve the above object, the technical scheme that the present invention takes is: the preparation method of the compound crucible using under a kind of ultra high temp, it is characterized in that, and the method is carried out according to following steps:
(A). tantalum crucible pre-treatment: tantalum crucible is immersed in sulphuric acid soln, depending on tantalum crucible surface clean level, soaks 30～120 minutes under sulphuric acid soln boils state, cooling post-flush, dry up;
(B). crucible assembly assembling: tantalum crucible is placed in plumbago crucible, placing graphite cup again in tantalum crucible, plumbago crucible, tantalum crucible, graphite cup three gap-fill carbon-based material, the peripheral parcel of plumbago crucible muff, reserved upper and lower two infrared pyrometer windows on muff;
(C). shove charge carbonization: the crucible assembly assembling is moved into induction heater, vacuumize, applying argon gas, intensification, monitoring plumbago crucible top and bottom temp, control plumbago crucible upper temp between 2100～2250 DEG C, pressure is between 20～200mbar, constant temperature time, between 10～50 hours, is then cooled to room temperature;
(D). remove carbon-based material: after cooling, in stove, take out the crucible assembly carbonization, graphite cup is taken out, remove after carbon-based material, then plumbago crucible, tantalum crucible and muff are re-assemblied;
(E). annealing thermal treatment: the crucible assembly re-assemblying is moved into induction heater, vacuumize, applying argon gas, intensification, monitoring plumbago crucible top and bottom temp, control plumbago crucible upper temp between 2000～2200 DEG C, pressure is between 20～500mbar, constant temperature time, between 5～30 hours, is then cooled to room temperature;
(F). cleaning-drying: after cooling, take out the crucible assembly after thermal treatment from stove, tantalum crucible is taken out, clean and dry up, prepare the smooth three layers of composite structured crucible of tantalum carbide-tantalum-carbonization.
Prepare the action principle of compound crucible: under high temperature, low pressure, inert gas environment, carbon-based material volatilization, the tantalum generation chemical reaction on carbon and tantalum crucible surface, generates the smooth upper layer of fine and close carbonization, and the reaction times is longer, and the smooth layer of carbonization is thicker.
The beneficial effect that the present invention produces is: take present method tantalum crucible directly can be changed into the smooth three layers of compound crucible of tantalum carbide-tantalum-carbonization.Eliminate tantalum crucible by annealing heat treatment process and changed into the carbonizing degree difference producing because of non-uniform temperature in the smooth three layers of compound crucible process of tantalum carbide-tantalum-carbonization, and eliminated crucible body internal stress.Compound crucible had both retained the unsuitable broken feature of high strength of tantalum, had had again the smooth high-temperature corrosion-resistance sexuality of carbonization, was not only applicable to the high-purity highly corrosive crystal growth of high temperature, also can be used for high-purity ceramic and the high-purity environment of high temperature such as fired.
Brief description of the drawings
Fig. 1 is the preparation flow figure of compound crucible of the present invention;
Fig. 2 is crucible assembly assembling schematic diagram of the present invention;
Fig. 3 is the smooth three layers of compound crucible structure schematic diagram of tantalum carbide-tantalum-carbonization of the present invention.
Embodiment
Below in conjunction with drawings and Examples, the invention will be further described: carbon-based material 4 of the present invention is carbon dust or carbon granule, and granularity is within the scope of 0.5 μ m～0.2mm, and purity is more than 99.95%.Muff 5 adopts the insulation hard felt of graphite and graphite soft felt to be processed into.Muff 5 adopts the hard felt material of graphite to be processed into hollow cylinder, and packs the size of hard felt muff 5 internal pores of graphite into according to plumbago crucible 1, can in the hard felt muff of graphite, spread and add graphite soft felt.The SIGRATHERM series insulating material that the hard felt of graphite and the optional Ge Li westerly of graphite soft felt group company produce, that this material has is high-purity, the feature of porous, light weight, easily processing, good heat insulating, long service life.
Embodiment: with reference to Fig. 1, the preparation method of the compound crucible using under a kind of ultra high temp carries out according to following steps:
Step 100(A), tantalum crucible pre-treatment: former tantalum crucible is immersed in sulphuric acid soln container, submergence completely, sulphuric acid soln container is heated on electromagnetic oven, be boiling state to sulphuric acid soln, under sulphuric acid soln boils state, soak 60 minutes cooling rear taking-up tantalum crucible, rinse well with deionized water, nitrogen dries up.
Step 110(B), crucible assembly assembling: tantalum crucible 2 is placed in plumbago crucible 1, placing graphite cup 3 again in tantalum crucible 2, graphite cup 3 wall thickness 2mm, the spacing between spacing, tantalum crucible 2 inwalls and graphite cup 3 outer walls between plumbago crucible 1 inwall and tantalum crucible 2 outer walls is all 3mm.At plumbago crucible 1, tantalum crucible 2 and graphite cup 3 three's gap-fill carbon-based materials 4, the present embodiment is selected carbon dust (high-purity), purity 99.99%, granularity 1 μ m.Cover plumbago crucible lid, its peripheral parcel muff 5, muff 5(upper cover and bottom) upper reserved upper and lower two infrared pyrometer windows 6, for infrared pyrometer monitoring plumbago crucible surface temperature, as shown in Figure 2.
Step 120(C), shove charge carbonization: the crucible assembly assembling is moved into induction heater, vacuumize, when vacuum tightness reaches 1 × 10
-5after mbar, applying argon gas (high-purity), pressure rises to 100mbar.Then repeat above-mentionedly to vacuumize applying argon gas process once.Induction heater applies power, heats up and starts, and with upper and lower infrared pyrometer, by the window monitoring plumbago crucible top on muff and the variation of plumbago crucible bottom temp, temperature rise rate is controlled within the scope of 2～8 DEG C/min.In the present embodiment, progressively heat up with 5 DEG C/min speed in plumbago crucible top, until plumbago crucible upper temp reaches 2200 DEG C, requires plumbago crucible top and the plumbago crucible bottom temperature difference to be no more than 50 DEG C, constant temperature time 30 hours simultaneously.Then delay and fall heating power, make plumbago crucible top slow cooling to room temperature, rate of temperature fall is controlled within the scope of 2～8 DEG C/min.In the present embodiment, rate of temperature fall is 5 DEG C/min.
Step 130(D), remove carbon-based material: after cooling, in stove, take out the crucible assembly carbonization, graphite cup is taken out, remove the carbon dust in plumbago crucible and tantalum crucible, then plumbago crucible, tantalum crucible and muff (not graphitiferous cup) are re-assemblied.
Step 140(E), annealing thermal treatment: the crucible assembly re-assemblying is moved into induction heater, vacuumize, when vacuum tightness reaches 1 × 10
-5after mbar, applying argon gas, pressure rises to 250mbar.Induction heater applies power, heats up and starts, and with upper and lower infrared pyrometer, by the window monitoring plumbago crucible top on muff and the variation of plumbago crucible bottom temp, temperature rise rate is controlled within the scope of 2～8 DEG C/min.In the present embodiment, progressively heat up with 5 DEG C/min speed in plumbago crucible top, until plumbago crucible upper temp reaches 2100 DEG C, requires plumbago crucible top and the plumbago crucible bottom temperature difference to be no more than 50 DEG C, constant temperature time 20 hours simultaneously.Then delay and fall heating power, make plumbago crucible top slow cooling to room temperature, rate of temperature fall is controlled within the scope of 2～8 DEG C/min.In the present embodiment, rate of temperature fall is 5 DEG C/min.
Step 150(F), cleaning-drying: after cooling, take out the crucible assembly after thermal treatment from stove, tantalum crucible is taken out, with deionized water, it is scrubbed, nitrogen dries up, and prepares the smooth three layers of composite structured crucible of tantalum carbide-tantalum-carbonization.
Prove through X-ray diffraction analysis, the crucible that utilizes this preparation method to obtain, the smooth three layers of compound crucible of tantalum carbide-tantalum-carbonization (as shown in Figure 3) are converted into, its outer wall is the smooth outer 2-1 of carbonization, centre is tantalum layer 2-2, inwall is the smooth internal layer 2-3 of carbonization, inside and outside layer of tantalum carbide carbonizing degree is even, because this kind of crucible is because of the existence of the smooth layer of carbonization, there is the resistance to corrosion to high temperature Al steam, nitrogen or other atmosphere, because of the reservation of inner tantalum layer, there is good intensity, anti-high and low-temp impacts, and should not ftracture.
Claims (2)
1. a preparation method for the compound crucible using under ultra high temp, is characterized in that, the method is carried out according to following steps:
(A). tantalum crucible pre-treatment: tantalum crucible is immersed in sulphuric acid soln, depending on tantalum crucible surface clean level, soaks 30～120 minutes under sulphuric acid soln boils state, cooling post-flush, dry up;
(B). crucible assembly assembling: tantalum crucible is placed in plumbago crucible, placing graphite cup again in tantalum crucible, plumbago crucible, tantalum crucible, graphite cup three gap-fill carbon-based material, carbon-based material is carbon dust or carbon granule, granularity is within the scope of 0.5 μ m～0.2mm, purity is more than 99.95%, and the peripheral parcel of plumbago crucible muff, reserves upper and lower two infrared pyrometer windows on muff;
(C). shove charge carbonization: the crucible assembly assembling is moved into induction heater, vacuumize, applying argon gas, intensification, monitoring plumbago crucible top and bottom temp, control plumbago crucible upper temp between 2100～2250 DEG C, plumbago crucible top and the bottom temperature difference are no more than 50 DEG C, control furnace pressure between 20～200mbar, constant temperature time, between 10～50 hours, is then cooled to room temperature; The rate-controlling heating up and lower the temperature is within the scope of 2～8 DEG C/min;
(D). remove carbon-based material: after cooling, in stove, take out the crucible assembly carbonization, graphite cup is taken out, remove after carbon-based material, then plumbago crucible, tantalum crucible and muff are re-assemblied;
(E). annealing thermal treatment: the crucible assembly re-assemblying is moved into induction heater, vacuumize, applying argon gas, intensification, monitoring plumbago crucible top and bottom temp, control plumbago crucible upper temp between 2000～2200 DEG C, plumbago crucible top and the bottom temperature difference are no more than 50 DEG C, pressure is between 20～500mbar, and constant temperature time, between 5～30 hours, is then cooled to room temperature; The rate-controlling heating up and lower the temperature is within the scope of 2～8 DEG C/min;
(F). cleaning-drying: after cooling, take out the crucible assembly after thermal treatment from stove, tantalum crucible is taken out and cleans and dry up, prepare the smooth three layers of composite structured crucible of tantalum carbide-tantalum-carbonization.
2. the preparation method of the compound crucible using under a kind of ultra high temp as claimed in claim 1, is characterized in that, described muff adopts the insulation hard felt of graphite and graphite soft felt to be processed into.
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| CN103643305A (en) * | 2013-12-04 | 2014-03-19 | 北京华进创威电子有限公司 | Preparation method of TaC crucible for high-temperature gas phase method crystal growth |
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| CN112159952B (en) * | 2020-10-10 | 2022-07-12 | 哈尔滨科友半导体产业装备与技术研究院有限公司 | Device and method capable of simultaneously carbonizing multiple tantalum sheets |
| CN112387974B (en) * | 2020-11-16 | 2023-03-17 | 哈尔滨科友半导体产业装备与技术研究院有限公司 | Preparation method of crucible material for growing aluminum nitride crystal by PVT method |
| CN115894035B (en) * | 2023-02-28 | 2023-12-15 | 中国电子科技集团公司第四十六研究所 | Preparation method of tantalum carbide crucible for growing aluminum nitride on silicon carbide |
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| CN101220521A (en) * | 2007-09-28 | 2008-07-16 | 中国科学院物理研究所 | Split type tantalum crucible and manufacturing method thereof |
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Application publication date: 20130424 Assignee: Tianjing Jinming Electronic Material LLC Assignor: China Electronics Science & Technology Group The 46th Institute Contract record no.: 2014120000109 Denomination of invention: Preparation method of combination type crucible utilized at ultra-high temperature Granted publication date: 20141001 License type: Exclusive License Record date: 20141217 |
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