A kind of ingot casting thermal field of the pure accurate monocrystalline of growing
Technical field
The present invention relates to a kind of ingot casting thermal field of the pure accurate monocrystalline of growing.
Background technology
Polycrystalline silicon ingot or purifying furnace is a kind of visual plant of the photovoltaic material of growing, and in the production, the polysilicon that will reach the certain purity requirement changes in the stove, comes out of the stove according to processing requirement heat fused, directional long crystal, thermal treatment, cooling.Make up the silicon crystal needed parts of growing and be referred to as thermal field, single for unmelted polycrystalline silicon provides a large amount of heat energy, in growing brilliant process, the polysilicon crystal of rational temperature gradient fields to obtain meeting the requirements is provided again.
Accurate monocrystalline is also referred to as the ingot casting monocrystalline, is the crystal that utilizes the directional solidification method growth to have single crystal-like silicon characteristic, and its growing principle is a traditional method of utilizing seed crystal revulsion growing single-crystal.Its main process is: at first place silicon single crystal as seed crystal in the quartz ceramic crucible bottom, and then load the silicon raw material above that, reduce the temperature of seed crystal bottom surface in the fusion stage through cooling quartz ceramic crucible bottom; Protection seed crystal bottom is not completely melted; Treat to begin long crystalline substance behind the seed crystal partial melting, in long brilliant process, because the design defect of traditional thermal field; The loss that type of thermal communication is crossed crucible wall causes the generation of the nucleus on the crucible inner wall surface and grows up; And the growth that makes progress along with crystal, crystal grain constantly extends to crystals, and area constantly increases.Therefore when using traditional polycrystalline ingot furnace to grow accurate monocrystalline crystal,, normally comprise the compound silicon chip of common polycrystalline of part (< 111>crystal orientation is main) and the accurate monocrystalline of part (< 100>crystal orientation) structure near 16 crystal bars of crucible wall.Difference because of the crystal orientation; When employing can be brought into play the alkali leather producing process manufacture batteries sheet of quasi-monocrystalline silicon sheet advantage; Because of the polycrystalline part is master's a crystal grain with < 111>crystal orientation, can not prepare the pyramid suede structure, make that the aberration of silicon chip two portions crystalline structure is apparent in view; Not only influence the outward appearance of battery sheet, also influence the efficiency of conversion of battery sheet.
Patent CN102140673 has proposed the separately polycrystalline silicon ingot or purifying furnace heating unit of control of a kind of top side well heater; To improving the crystal ingot later stage; The crystalizing interface of position, germ nucleus plays good effect; But does not significantly improve at the interface near the crucible wall, and the small grains that sidewall of crucible is looked unfamiliar still can inwardly be grown.And in long brilliant first half; Crystal is in below the side well heater; Because the crucible wall is all around away from the side well heater; Also make a large amount of small grains generate to heat radiation all around, destroy the crystalline structure of single crystal growing, be difficult to realize that all 25 spillikins 100% are complete accurate single crystal structure with the crucible wall and to the crystal ingot growth inside.
Patent CN202054920 has proposed a kind of device that is used for directional solidification method growing single-crystal silicon, and its implementation is at crucible bottom arranged outside heat insulation device, the heat radiation that stops crucible to be avoided; For the certain function that is formed with that suppresses crucible wall place nucleus; But because of mode of operation is passive insulation, can not suppress the formation and the growth of new nucleus on the preceding crucible wall of crystalizing interface fully, and the transition of crucible wall is incubated; The center crystalizing interface is unfavorable for the raising of crystal mass with epirelief.
Summary of the invention
The technical problem that the present invention will solve is: overcome the deficiency of prior art, a kind of ingot casting thermal field of the pure accurate monocrystalline of growing is provided, the ratio of the pure accurate monocrystalline crystal bar of growing is higher.
The technical solution adopted for the present invention to solve the technical problems is: a kind of ingot casting thermal field of the pure accurate monocrystalline of growing; Have upper furnace body, lower furnace body; Be provided with quartz ceramic crucible in the cavity that described upper furnace body, lower furnace body form; Described quartz ceramic crucible outer exterior wall is provided with the sidepiece primary heater; Described quartz ceramic crucible top is provided with the top primary heater, is provided with portable secondary heater between described quartz ceramic crucible outer wall and the sidepiece primary heater, and described portable secondary heater is connected with the secondary heater electrode; Described secondary heater electrode passes upper furnace body and is connected with secondary heater electrode running gear; Described secondary heater electrode running gear is installed on the upper furnace body, and it is upper and lower mobile that described secondary heater electrode running gear drives portable secondary heater through the secondary heater electrode, and the bottom-up mobile velocity curve of described portable secondary heater is consistent with the brilliant velocity curve of length of seed of single crystal silicon in the quartz ceramic crucible.
Further, described portable secondary heater is an annular, and described portable secondary heater is around one week of outer wall wall of quartz ceramic crucible.
Further, described secondary heater electrode is along equally distributed three electrode bars of circumference, and three electrode bars all are connected with the portable secondary heater of annular.
Further; Described quartz ceramic crucible places in the plumbago crucible, and described plumbago crucible bottom is provided with graphite and helps grumeleuse, and described graphite helps grumeleuse to be supported by pillar stiffener; Be added with silicon solution in the described quartz ceramic crucible; Described plumbago crucible is positioned at the incubation cavity sidewall of bottom opening, and described sidepiece primary heater is between incubation cavity sidewall and plumbago crucible outer wall, and described portable secondary heater is between plumbago crucible outer wall and sidepiece primary heater; Described sidepiece primary heater and top primary heater are connected with the primary heater electrode, and described incubation cavity sidewall and incubation cavity base plate break away from the formation gap.
The invention has the beneficial effects as follows: the present invention is through increasing portable secondary heater; In long brilliant process, keep the solid-liquid interface in portable secondary heater and the quartz ceramic crucible to be in sustained height; Under the drive of secondary heater electrode, move on along with boosting of crystalizing interface.Because the bottom-up mobile velocity curve of portable secondary heater is consistent with the brilliant velocity curve of length of seed of single crystal silicon in the quartz ceramic crucible; The heat effect of portable secondary heater can effectively stop the hot-fluid heat radiation of solid-liquid interface place quartz ceramic crucible sidewall; Feasible solid-liquid interface near the quartz ceramic crucible wall is a level or slightly protruding; Thereby the generation of nucleus and inwardly growth on the quartz ceramic crucible wall in prevention solid-liquid interface forward position; The influence that the accurate monocrystalline crystalline structure that the seed crystal inducing action that makes produces is not newly produced crystal grain by quartz ceramic crucible wall place, the ratio of the pure accurate monocrystalline crystal bar of growing is higher.
Description of drawings
Below in conjunction with accompanying drawing the present invention is further specified.
Fig. 1 is a structural representation of the present invention;
Wherein: Fig. 1, a kind of ingot casting thermal field synoptic diagram of pure accurate monocrystalline fully of growing
Wherein, 1. incubation cavity sidewall pull bar, 2. incubation cavity top board, 3. quartz ceramic crucible, 4. plumbago crucible; 5. graphite helps grumeleuse, 6. lower furnace body, 7. pillar stiffener, 8. primary heater electrode, 9. gas cylinder; 10. secondary heater electrode running gear, 11. secondary heater electrodes, 12. upper furnace bodies, 13. sidepiece primary heaters, 14. silicon solution; 15. portable secondary heater, 16. incubation cavity sidewalls, 17. silicon crystal, 18. incubation cavity base plates.
Embodiment
Combine accompanying drawing that the present invention is further described now.These accompanying drawings are the synoptic diagram of simplification substruction of the present invention only are described in a schematic way, so it only shows the formation relevant with the present invention.
As shown in Figure 1, a kind of ingot casting thermal field of the pure accurate monocrystalline of growing has upper furnace body 12, lower furnace body 6; Be provided with quartz ceramic crucible 3 in the cavity that upper furnace body 12, lower furnace body 6 form; Quartz ceramic crucible 3 places in the plumbago crucible 4, and plumbago crucible 4 bottoms are provided with graphite and help grumeleuse 5, and graphite helps grumeleuse 5 to be supported by pillar stiffener 7; Be added with silicon solution 14 in the quartz ceramic crucible 3; Silicon solution 14 bottoms form silicon crystal 17 in long brilliant process, silicon solution 14 tops of quartz ceramic crucible 3 are provided with gas cylinder 9 to upper furnace body 12 tops, and plumbago crucible 4 is positioned at the incubation cavity sidewall 16 of bottom opening.
Quartz ceramic crucible 3 tops are provided with the top primary heater; Sidepiece primary heater 13 is between incubation cavity sidewall 16 and plumbago crucible 4 outer walls; Portable secondary heater 15 is between plumbago crucible 4 outer walls and sidepiece primary heater 13; Sidepiece primary heater 13 is connected with primary heater electrode 8 with the top primary heater, and incubation cavity sidewall 16 breaks away from the formation gap with incubation cavity base plate 18, and incubation cavity sidewall 16 tops are connected with 2 sealings of incubation cavity top board.
If outside the quartz ceramic crucible 3 plumbago crucible 4 is not set, sidepiece primary heater 13 is between incubation cavity sidewall 16 and quartz ceramic crucible 3 outer walls, and portable secondary heater 15 is between quartz ceramic crucible 3 outer walls and sidepiece primary heater 13.
Portable secondary heater 15 is connected with secondary heater electrode 11; Secondary heater electrode 11 passes upper furnace body 12 and is connected with secondary heater electrode running gear 10; Secondary heater electrode running gear 10 is installed on the upper furnace body 12; Secondary heater electrode running gear 10 drives portable secondary heater 15 upper and lower moving through secondary heater electrode 11, and portable secondary heater 15 bottom-up mobile velocity curves are consistent with the brilliant velocity curve of length of seed of single crystal silicon in the quartz ceramic crucible 3.
Portable secondary heater 15 is an annular, and portable secondary heater 15 is around one week of outer wall wall of quartz ceramic crucible 3.Secondary heater electrode 11 is along equally distributed three electrode bars of circumference, and three electrode bars all are connected with the portable secondary heater 15 of annular.
Use-pattern one:
The power of portable secondary heater 15 is fixed as 3kw; The bottom-up translational speed of portable secondary heater 15 is consistent with the brilliant velocity curve of length of quartz ceramic crucible 3 interior seed of single crystal silicon; By 15cm/h to 10cm/h; The accurate monocrystalline crystal bar that grows detects through behind the evolution, and all crystal bars all do not comprise common poly grains, and promptly pure accurate monocrystalline crystal bar ratio has reached 100%.
Use-pattern two:
The power variation interval of portable secondary heater 15 is 3~10kw; The bottom-up translational speed of portable secondary heater 15 is consistent with the brilliant velocity curve of length of quartz ceramic crucible 3 interior seed of single crystal silicon; By 20cm/h to 10cm/h; The accurate monocrystalline crystal bar that grows detects through behind the evolution, and all crystal bars are the pure accurate monocrystalline crystal bar that does not comprise poly grains fully.
The present invention keeps portable secondary heater 15 highly unified with the solid-liquid interface in the quartz ceramic crucible 3 in long brilliant process through increasing portable secondary heater, under the drive of secondary heater electrode 11, moves on along with boosting of crystalizing interface.Because portable secondary heater 15 bottom-up mobile velocity curves are consistent with the brilliant velocity curve of length of silicon crystal in the quartz ceramic crucible 3; The heat that portable secondary heater 15 sends has stoped the hot-fluid of quartz ceramic crucible 3 to sidewall; Feasible solid-liquid interface near quartz ceramic crucible 3 walls is a level or slightly protruding; Thereby the generation of nucleus and inwardly growth on quartz ceramic crucible 3 walls in prevention solid-liquid interface forward position; The influence that the accurate monocrystalline crystalline structure that the seed crystal inducing action that makes produces is not newly produced crystal grain by quartz ceramic crucible wall place obtains 100% pure accurate single crystal structure, and the ratio of the pure accurate monocrystalline crystal bar of growing is higher.
After adopting the present invention, 25 crystal bars of growth monocrystalline crystal bar that all is as the criterion, the earning rate of promptly accurate monocrystalline crystal bar is 100%, and the earning rate of the accurate monocrystalline crystal bar of common ingot casting thermal field is merely 36%, is three times of the earning rate of traditional quasi-monocrystalline silicon sheet.Thereby greatly reduce accurate monocrystalline crystalline production cost, improved the total quality of accurate monocrystalline crystal ingot.
With above-mentioned foundation desirable embodiment of the present invention is enlightenment, and through above-mentioned description, the related work personnel can carry out various change and modification fully in the scope that does not depart from this invention technological thought.The technical scope of this invention is not limited to the content on the specification sheets, must confirm its technical scope according to the claim scope.