A kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed
Technical field
The present invention relates to the single crystal growing furnace in vertical pulling method single crystal growing field, especially relate to a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed.
Background technology
When vertical pulling method single crystal growing, first raw material, doping agent are melted in crucible, then use the monocrystalline in certain crystal orientation as seed crystal, from top, insert melt, through seeding, shouldering, after turning shoulder, progressively with certain diameter, upwards lift, and then make melt take seed crystal according to certain speed, to grow into single crystal as seed.
From thermally equilibrated angle, the speed of growth formula that can derive single crystal is:
VpHA=K
SG
S-K
LG
L (1)
Wherein: V-growth rate of single crystals;
P-single crystal density;
The latent heat of H-melt;
The area at A-single crystal growth interface;
K
sthe thermal conductivity of-solid;
G
sthe thermograde of-solid;
K
lthe thermal conductivity of-liquid;
G
lthe thermograde of-liquid.
From formula (1), the single crystal of growth certain diameter, under the constant prerequisite of other condition, by the heat radiation of strengthening single crystal, especially near the heat radiation of single crystal growth interface, and then near single crystal thermograde increase growth interface, be the effective way that improves growth rate of single crystals.
Conventional vertical pulling method monocrystal thermal-field, be on melt top, single crystal around places a guide shell, be used for shielding well heater and the direct radiation of high-temperature fusant to single crystal, near concentrated the flowing through growth interface of argon gas that guide shell blows concubine downwards simultaneously, and then the heat radiation of strengthening single crystal, increase single crystal thermograde.But increase merely guide shell, can not be from strengthening in essence scattering and disappearing of single crystal heat, the effect that increases single crystal thermograde is also not obvious, and it is limited that growth rate of single crystals promotes amplitude.
Publication number is that the Chinese invention patent (application number 200910099830.3) of CN101575731A discloses the vertical pulling silicon single crystal growing furnace with water-cooling jacket, it utilizes the heat loss of water coolant strengthening single crystal rod, but cool position is far away apart from growth interface, increase DeGrain near single crystal thermograde growth interface, the amplitude that pulling rate promotes is limited.Because water-cooling jacket needs welding, there is the risk that water coolant is revealed, single crystal growing furnace explodes simultaneously.
Publication number is that the Chinese invention patent (application number 201110062659.6) of CN102102219A discloses a kind of refrigerating unit that improves the single crystal growing furnace speed of growth, its water cooler is close to heat shielding inner side and is placed, water cooler is connected on stove cylinder by pipe connecting, and then strengthens to a certain extent near the single crystal heat loss of growth interface.But water cooler is close to heat shielding inner side and is placed; when taking away single crystal dissipated heat; also taken away the heat of heat shielding; increase well heater and maintained the crystal required power of growing; the unobstructed protection in water cooler lower end, silicon melt is easily splashed on water cooler, and water cooler is connected on stove cylinder by pipe connecting simultaneously; each produces heat needs manually to take out water cooler and pipe connecting at dismounting thermal field, when filling with substance, has increased direct labor's labour intensity.
Summary of the invention
The object of the invention is to overcome the deficiencies in the prior art, a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed is provided.
To achieve these goals, the present invention adopts following technical scheme:
A kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed, it comprises guide shell, it is characterized in that, in described guide shell, be provided with refrigerating unit, this refrigerating unit comprises the molybdenum cylinder (4) around guide shell inwall, the inner side of molybdenum cylinder (4) is around hollow coiling copper pipe (3) is set, the two ends of described hollow coiling copper pipe reach the import that single crystal growing furnace one end outside and this hollow coiling copper pipe is heat-eliminating medium, the other end is the outlet of heat-eliminating medium, and described hollow coiling copper pipe inside is full of mobile heat-eliminating medium.
As a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed of the present invention, comparatively it is desirable to, the inner side of described hollow coiling copper pipe is also connected with copper cylinder (2).
As a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed of the present invention, comparatively it is desirable to, described copper cylinder is reverse frustoconic.
As a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed of the present invention, comparatively it is desirable to, the tapering of described hollow coiling copper pipe is 0 °~80 °, and according to spirrillum or a few word shape coiling, bell joint flange or bell from single crystal growing furnace after coiling pass stove.
As a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed of the present invention, comparatively it is desirable to, described heat-eliminating medium is water, argon gas or helium.
As a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed of the present invention, comparatively it is desirable to, the tapering of described copper cylinder (2) is 0 °~80 °, emittance >=0.7.
As a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed of the present invention, comparatively it is desirable to, gap in the bottom diameter of described copper cylinder (2) and single crystal growing furnace between crystal diameter is at 10~60mm, and copper cylinder bottom diameter and guide shell bottom diameter difference are 0~30mm.
As a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed of the present invention, comparatively it is desirable to, the tapering of described molybdenum cylinder is 0 °~80 °, and the gap between molybdenum cylinder inner side and coiling copper pipe is 0~30mm, and the gap between molybdenum cylinder outside and guide shell is 0~30mm.
As a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed of the present invention, comparatively it is desirable to, the height of described refrigerating unit is the crystal diameter of having grown 0.2~5 times, the upper plane clearance of the lower surface of refrigerating unit and guide shell lower end is 0~30mm.
As a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed of the present invention, comparatively it is desirable to, described guide shell lower end is provided with protection elbow (9).
The present invention has following beneficial effect: whole copper pipe of inner logical heat-eliminating medium is according to tapering coiling, from bell flange or bell, pass, outside stove, be connected with heat-eliminating medium inlet and outlet piping, welding in stove, stopped the possibility that heat-eliminating medium is revealed, refrigerating unit, by the vertical landing of bell and transverse shifting, is convenient to the cleaning of workman's thermal field and charging work.The thermal conductivity >400w/m.k of copper, semicircle or rectangle that coiling copper pipe cross section is hollow, and fully welding contact between copper cylinder, the surface of copper cylinder can guarantee temperature lower and that be evenly distributed, the internal surface of copper cylinder is processed through physical method or chemical process, emittance >=0.7, the fully radiant heat of absorbing crystal.In thermal field, adopt described refrigerating unit, in crystal growing process, near crystalline temp growth interface is up to more than 1,000 degree, pass through hyperthermia radiation, copper cylinder and heat-eliminating medium can carry out sufficient heat exchange with crystal, lead away in time heat, improve near the thermograde (seeing the analog calculation result of accompanying drawing 4 and accompanying drawing 5) of the crystal of growth interface, and then significantly improve the speed of growth of single crystal.The bottom diameter of copper cylinder is more than or equal to the bottom diameter of guide shell, can avoid melt to be splashed to refrigerating unit.The emittance of molybdenum cylinder is low, can effectively reduce the calorific loss from guide shell, and then reduces heater power.When common 22 inch thermal fields draw 8 cun of silicon single crystaies, the average crystalline speed of growth is generally at 0.9~1.1mm/min, and adopts the thermal field of described refrigerating unit, more than the average crystalline speed of growth can reach 1.4mm/min.Described refrigerating unit can be applied to the transformation of existing table, also can be applicable to the manufacture processing of new table.
Accompanying drawing explanation
Fig. 1 is a kind of sectional view that improves the single crystal growing furnace of vertical pulling method single crystal growing speed in embodiment 1.
Fig. 2 is I place enlarged view in Fig. 1.
Fig. 3 is a kind of sectional view that improves the single crystal growing furnace of vertical pulling method single crystal growing speed in embodiment 2, and it shows coiling copper pipe and passes in another way single crystal growing furnace.
Fig. 4 is a kind of sectional view that improves the single crystal growing furnace of vertical pulling method single crystal growing speed in embodiment 3, and wherein, copper cylinder, coiling copper pipe, the another kind of mode of molybdenum cylinder combine.
Fig. 5 is the schematic diagram of coiling copper pipe spirrillum coiling in a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed.
Fig. 6 is a few word shape coiling copper pipe schematic diagram in a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed.
Fig. 7 a, 7b, for being in embodiment 4, are used the original thermal field of certain single crystal growing furnace, the power of applying this refrigerating unit thermal field and the temperature distribution schematic diagram of analogue simulation computed in software.
Fig. 8 is the embodiment 4 original thermal field of certain single crystal growing furnace that uses analogue simulation computed in software, improve thermal field, use stainless steel water cooling plant thermal field, use near the radial symmetry gradient analog calculation result schematic diagram of the single crystal growth interface of this refrigerating unit thermal field.
Reference numeral in figure: 1-crystal; 2-copper cylinder; 3-coiling copper pipe; 4-molybdenum cylinder; 5-guide shell; 6-melt; 7-bell; 8-bell joint flange; 9-protects elbow.
Embodiment
For technique means, creation characteristic that the present invention is realized, reach object and effect is easy to understand, below in conjunction with concrete diagram, further set forth the present invention.
A kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed, comprise guide shell, refrigerating unit is set in guide shell, refrigerating unit comprises the two-layer component combination with tapering, described component combination is outermost molybdenum cylinder, and internal layer is the hollow coiling copper pipe of logical heat-eliminating medium.
The invention also discloses the another kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed, comprise guide shell, refrigerating unit is set in guide shell, refrigerating unit comprises three layers of component combination with tapering, described component combination is outermost molybdenum cylinder, the coiling copper pipe of the logical heat-eliminating medium in inside in middle layer, the copper cylinder of innermost layer.Described refrigerating unit is formed by three layers of component combination with tapering, and outermost layer is molybdenum cylinder, and middle layer is the coiling copper pipe of inner logical heat-eliminating medium, and innermost layer is copper cylinder.Guide shell lower end is provided with protection elbow.Fully welding contact between copper cylinder and coiling copper pipe.The bottom diameter of copper cylinder is more than or equal to the bottom diameter of guide shell.Middle layer is the coiling copper pipe of inner logical heat-eliminating medium, and tapering is 0 °~80 °, and according to spirrillum or the coiling of a few word shape, bell joint flange or bell from single crystal growing furnace after coiling pass stove, is then connected with the heat-eliminating medium turnover pipeline of equipment of furnace chassis.Middle layer is the coiling copper pipe of inner logical heat-eliminating medium, and heat-eliminating medium is the cooling fluids such as water, argon gas, helium.Middle layer is the coiling copper pipe of inner logical heat-eliminating medium, between coiling copper pipe and copper cylinder, for abundant face, contact, such as the cross section of coiling bobbin is processed into semicircle or the rectangle of hollow, between coiling copper pipe and copper cylinder, by silver soldering, connect or copper silver soldering connects, carry out fully welding contact.Innermost layer is copper cylinder, and tapering is 0 °~80 °, and emittance >=0.7 is processed through chemical process or physical method (as oxidation blackout, surfaceness increase etc.) in copper cylinder surface.Innermost layer is copper cylinder, and the gap between copper cylinder bottom diameter and crystal diameter is at 10~60mm, and the value that copper cylinder bottom diameter deducts guide shell bottom diameter is 0~30mm.Outermost layer is molybdenum cylinder, and tapering is 0 °~80 °, and the gap between molybdenum cylinder inner side and coiling copper pipe is at 0~30mm, and the gap between molybdenum cylinder outside and guide shell is at 0~30mm.Described refrigerating unit is formed by three layers of component combination with tapering, and outermost layer is molybdenum cylinder, and middle layer is the coiling copper pipe of inner logical heat-eliminating medium, and innermost layer is copper cylinder.The height of refrigerating unit is 0.2~5 times of crystal diameter.The upper plane clearance of the lower surface of refrigerating unit and guide shell lower end is 0~30mm.The distance of the lower surface of refrigerating unit and melt upper surface is 10~200mm.
Embodiment 1
As depicted in figs. 1 and 2, the present embodiment is a kind of single crystal growing furnace that improves vertical pulling method single crystal growing speed, comprise guide shell, in guide shell, be provided with refrigerating unit, this refrigerating unit is formed by three layers of component combination with tapering, and outermost layer is molybdenum cylinder 4, and for inner logical water coolant, (heat-eliminating medium includes but not limited to water in middle layer, can also be other cooling fluids such as argon gas or helium) hollow coiling copper pipe 3, innermost layer is copper cylinder 2.Gap between molybdenum cylinder 4 inner sides and coiling copper pipe 3 is at 0~30mm, and the gap between molybdenum cylinder 4 outsides and guide shell 5 is at 0~30mm.The coiling copper pipe 3 of inner logical water coolant, tapering is 0 °~80 °, as shown in Figure 5 according to spirrillum coiling, the bell joint flange 8 from single crystal growing furnace after coiling passes stove, is then connected with the water coolant turnover pipeline of equipment of furnace chassis.Between coiling copper pipe 3 and copper cylinder 2, for abundant face, contact, the cross section of coiling bobbin 3 is processed into semicircle or the rectangle of hollow, connects or copper silver soldering connects between coiling copper pipe 3 and copper cylinder 2 by silver soldering, carries out fully welding contact.Described guide shell lower end is provided with protection elbow 9.The tapering of copper cylinder 2 is 0 °~80 °, and emittance >=0.7 is processed through chemical process or physical method (as oxidation blackout, surfaceness increase etc.) in surface.Gap between copper cylinder 2 bottom diameters and crystal 1 diameter is at 10~60mm, and the value that copper cylinder 2 bottom diameters deduct guide shell 5 bottom diameters is 0~30mm.The tapering of molybdenum cylinder 4 is 0 °~80 °.The height of refrigerating unit is 0.2~5 times of crystal 1 diameter.The upper plane clearance of the lower surface of refrigerating unit and guide shell 5 lower ends is 0~30mm.The distance of the lower surface of refrigerating unit and melt 6 upper surfaces is 10~200mm.
The thermal conductivity >400w/m.k of copper, semicircle or rectangle that coiling copper pipe 3 cross sections of inner logical water coolant are hollow, and between copper cylinder 2, by silver soldering, connect or copper silver soldering connects, guarantee abundant face contact, the surface of copper cylinder 2 can guarantee temperature lower and that be evenly distributed, the internal surface of copper cylinder 2 is processed through physical method or chemical process, emittance >=0.7, the fully radiant heat of absorbing crystal 1.In thermal field, adopt described refrigerating unit, in crystal growing process, near crystal 1 temperature growth interface is up to more than 1,000 degree, pass through hyperthermia radiation, copper cylinder 2 can carry out sufficient heat exchange with crystal 1, lead away in time heat, improve near the thermograde of the crystal 1 of growth interface, and then significantly improve the speed of growth of single crystal 1.
Embodiment 2
As shown in Figure 3, coiling copper pipe 3 another kinds of the refrigerating unit in the present embodiment single crystal growing furnace pass single crystal growing furnace external square type.The coiling copper pipe 3 of inner logical water coolant, according to the coiling of spirrillum shape, the bell 7 from single crystal growing furnace after coiling passes stove, is then connected with the water coolant turnover pipeline of equipment of furnace chassis.Rest part is identical with embodiment 1.
Embodiment 3
As shown in Figure 4, the outermost layer of the refrigerating unit in the present embodiment single crystal growing furnace is molybdenum cylinder 4, middle layer copper cylinder 2, and innermost layer is the coiling copper pipe 3 of inner logical water coolant.Gap between molybdenum cylinder 4 inner sides and copper cylinder 2 is at 0~30mm, and the gap between molybdenum cylinder 4 outsides and guide shell 5 is at 0~30mm.The coiling copper pipe 3 of inner logical water coolant, tapering is 0 °~80 °, as shown in Figure 5, according to the coiling of spirrillum shape, bell joint flange 8 or bell 7 from single crystal growing furnace after coiling pass stove, are then connected with the water coolant turnover pipeline of equipment of furnace chassis.Between coiling copper pipe 3 and copper cylinder 2, for abundant face, contact, the cross section of coiling bobbin 3 is processed into semicircle or the rectangle of hollow, connects or copper silver soldering connects between coiling copper pipe 3 and copper cylinder 2 by silver soldering, carries out fully welding contact.The tapering of copper cylinder 2 is 0 °~80 °, and emittance >=0.7 is processed through chemical process or physical method (as oxidation blackout, surfaceness increase etc.) in surface.Gap between coiling copper pipe 3 bottom diameters and crystal 1 diameter is at 10~60mm, and the value that coiling copper pipe 3 bottom diameters deduct guide shell 5 bottom diameters is 0~30mm.The tapering of molybdenum cylinder 4 is 0 °~80 °.The height of refrigerating unit is 0.2~5 times of crystal 1 diameter.The upper plane clearance of the lower surface of refrigerating unit and guide shell 5 lower ends is 0~30mm.The distance of the lower surface of refrigerating unit and melt 6 upper surfaces is 10~200mm.
Embodiment 4
According to the present invention, transform domestic certain type 950 single crystal growing furnace, 22 inch thermal fields, 135Kg feeds intake, draw 8 inches of silicon single crystaies, conventional thermal field, the average crystalline speed of growth is at 0.9mm/min, and adopting thermal field of the present invention, the average crystalline speed of growth can reach 1.5mm/min.Apply thermal field of the present invention, crystal growth time can save 30%.
For further confirming effect, for the structure of embodiment 1, use analogue simulation software to carry out Simulation Analysis to the thermal field of original thermal field of certain single crystal growing furnace and this refrigerating unit of application, see Fig. 7 a, 7b and Fig. 8.Shown in Fig. 7 a, 7b is the analog calculation result that original 22 inch thermal fields of certain single crystal growing furnace draw 8 inches of single crystal rod (Org) and application this refrigerating unit thermal field (Copper).From Fig. 7 a, 7b, apply the thermal field of this refrigerating unit and compare with original thermal field, can promote the heat loss of crystal bar.Shown in Fig. 8 is the original thermal field of certain single crystal growing furnace, improvement thermal field, the use stainless steel water cooling plant thermal field that uses analogue simulation computed in software, the radial symmetry gradient analog calculation result of using near the single crystal of growth interface of this refrigerating unit thermal field.As shown in Figure 8, apply this refrigerating unit thermal field, near growth interface, the radial symmetry gradient increase of crystal is the most obvious.
Embodiment 5
In the present embodiment, the coiling copper pipe of hollow adopts a few font coilings, and rest part is identical with embodiment 1.
The foregoing is only the preferred embodiment of the present invention, protection scope of the present invention is not limited in above-mentioned embodiment, and every technical scheme that belongs to the principle of the invention all belongs to protection scope of the present invention.For a person skilled in the art, some improvement of carrying out under the prerequisite that does not depart from principle of the present invention, these improvement also should be considered as protection scope of the present invention.