WO2013149559A1 - 一种多晶硅锭及其制备方法和多晶硅片 - Google Patents

一种多晶硅锭及其制备方法和多晶硅片 Download PDF

Info

Publication number
WO2013149559A1
WO2013149559A1 PCT/CN2013/073361 CN2013073361W WO2013149559A1 WO 2013149559 A1 WO2013149559 A1 WO 2013149559A1 CN 2013073361 W CN2013073361 W CN 2013073361W WO 2013149559 A1 WO2013149559 A1 WO 2013149559A1
Authority
WO
WIPO (PCT)
Prior art keywords
silicon
nucleation
polycrystalline silicon
crucible
microcrystalline
Prior art date
Application number
PCT/CN2013/073361
Other languages
English (en)
French (fr)
Inventor
万跃鹏
何亮
胡动力
雷琦
张涛
钟德京
陈红荣
张学日
Original Assignee
江西赛维Ldk太阳能高科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN201210096209.3A external-priority patent/CN102776554B/zh
Priority claimed from CN201210096291.XA external-priority patent/CN102776561B/zh
Priority claimed from CN201310033073.6A external-priority patent/CN103074669B/zh
Application filed by 江西赛维Ldk太阳能高科技有限公司 filed Critical 江西赛维Ldk太阳能高科技有限公司
Publication of WO2013149559A1 publication Critical patent/WO2013149559A1/zh

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B28/00—Production of homogeneous polycrystalline material with defined structure
    • C30B28/04—Production of homogeneous polycrystalline material with defined structure from liquids
    • C30B28/06—Production of homogeneous polycrystalline material with defined structure from liquids by normal freezing or freezing under temperature gradient
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B11/00—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/02—Elements
    • C30B29/06—Silicon

Definitions

  • the present invention relates to the field of semiconductor fabrication, and more particularly to a polycrystalline silicon ingot, a method of fabricating the same, and a polycrystalline silicon wafer.
  • the preparation method of the polycrystalline silicon ingot mainly adopts the directional solidification system method (DSS) furnace crystal growth technology provided by GT Solar, and the method generally includes steps of heating, melting, solidification, annealing, and cooling.
  • DSS solidification system method
  • the molten silicon material spontaneously forms a random nucleation and a random nucleation gradually grows along with the continuous cooling of the crucible bottom.
  • the initial nucleation is not controlled, In the nucleation process, dislocations are easily generated, resulting in disordered crystal orientation and uneven grain entanglement. Therefore, the quality of the polycrystalline silicon ingot prepared by the method is low.
  • the solar cell produced by using the polycrystalline silicon ingot has low photoelectric conversion efficiency. Therefore, in order to obtain a high quality polycrystalline silicon ingot having a low dislocation density and few defects, a polycrystalline silicon ingot casting method capable of effectively obtaining a good initial nucleation becomes important.
  • the present invention aims to provide a method for preparing a polycrystalline silicon ingot, which can obtain a good initial nucleation of a polycrystalline silicon ingot, reduce dislocation propagation of a polycrystalline silicon ingot during growth, and obtain a high quality polycrystalline silicon ingot. .
  • the present invention also provides a high quality polycrystalline silicon ingot obtained by the preparation method, and a polycrystalline silicon wafer obtained by using the polycrystalline silicon ingot as a raw material.
  • the present invention provides a method for preparing a polycrystalline silicon ingot, comprising:
  • the silicon melt can form a plurality of uniformly distributed nucleation sources on the non-silicon material nucleation source layer, so that the polycrystalline silicon ingot obtains a good initial nucleation, thereby growing a dominant crystal.
  • the crystal of the direction can form a plurality of uniformly distributed nucleation sources on the non-silicon material nucleation source layer, so that the polycrystalline silicon ingot obtains a good initial nucleation, thereby growing a dominant crystal.
  • the crystal of the direction is a plurality of uniformly distributed nucleation sources on the non-silicon material nucleation source layer
  • the method for preparing the polycrystalline silicon ingot includes:
  • a porous material is laid on the bottom of the crucible to form a non-silicon material nucleation source layer, and then the silicon material is filled on the porous material;
  • the silicon melt interface is moved away from the bottom of the crucible, and after the directional crystal is solidified, it is annealed and cooled to obtain a polycrystalline silicon ingot.
  • the porous material is a material having a melting point greater than the melting point of silicon and not reacting with silicon at a high temperature.
  • the porous material is silicon nitride, silicon carbide or quartz.
  • the porous material has a pore diameter of from 0.1 cm to 5 cm.
  • the porous material has a thickness of 0.1 to 2 cm.
  • the porous material has a size of 10 X 10 mm to 155 155 mm.
  • a porous material such as silicon nitride, silicon carbide or quartz has a plurality of pores, in the melting stage of the silicon material, the silicon melt formed by melting the silicon material is filled in the pores, and in the initial nucleation stage, in the supercooled state, silicon The melt undergoes free nucleation crystallization in the pores. In this case, the nucleation crystallization process is not completed in a large plane, but in a myriad of small pores, thus controlling the occurrence and growth of a large number of dendrites. .
  • the temperature is controlled so that the silicon melt filled in the pores first reaches a supercooled state, so that the polycrystalline silicon ingot obtains a good initial nucleation, thereby growing a crystal having a dominant crystal orientation.
  • the silicon material further comprising laying a layer of silicon scrap over the porous material.
  • the silicon scrap is one or more of a single crystal silicon scrap, a polycrystalline silicon scrap, and an amorphous silicon scrap.
  • the silicon scrap has a size of from 0.1 cm to 10 cm.
  • the silicon scrap is laid to a thickness of 0.5 cm to 5 cm.
  • the silicon material paving is disorderly arranged at the bottom of the crucible.
  • the scrap layer forms a scaffold structure.
  • the scaffold structure has numerous holes. During the melting stage of the silicon material, the silicon melt formed by melting the silicon material will be filled in the holes. In the nucleation stage, in the supercooled state, a plurality of nucleation sources with a uniform hook distribution are formed on the silicon particle level, so that the polycrystalline silicon ingot obtains a good initial nucleation, thereby growing a crystal having a dominant crystal orientation.
  • the temperature is controlled such that the silicon melt at the solid-liquid interface formed by the silicon melt and the unmelted silicon material and the silicon melt filled in the pores are first subcooled, preferentially nucleated, and then the silicon melt The interface moves away from the bottom of the crucible, and the silicon melt crystallizes and solidifies.
  • the initial nucleation of the polycrystalline silicon ingot is well controlled, from The crystals which are favored by the crystal orientation are grown, so that a large amount of dislocations can be prevented from proliferating, and a high-quality polycrystalline silicon bond can be obtained.
  • the arrangement of the silicon nitride layer on the inner wall of the crucible can effectively prevent impurities at the bottom of the crucible from entering the crystal, thereby improving the quality of the polycrystalline silicon ingot.
  • the method for preparing the polycrystalline silicon ingot includes:
  • the nucleation source is selected from a silicon-based compound that is close to the crystal lattice of the silicon material and/or a material that reacts with the silicon material to form a silicon-based compound, or a mixture of silicon powder, a silicon-based compound that is close to the crystal lattice of the silicon material, and a material that reacts with the silicon material to form a silicon-based compound and silicon nitride;
  • the form of the nucleation source in the step (1) is not limited.
  • the nucleation source is disposed to set the nucleation source coating at the bottom of the crucible, or to lay the nucleation source directly at the bottom of the crucible.
  • the nucleation source has a particle size of 0.1 um to 1 cm.
  • the silicon-based compound close to the crystal lattice of the silicon material is silicon carbide powder or quartz powder.
  • the material which reacts with the silicon material to form a silicon-based compound is carbon powder.
  • the finger according to the present invention refers to a container in which a polycrystalline silicon ingot is grown, and its shape and kind are not limited.
  • the heat field in the crucible is controlled to cool the silicon material in a molten state, and after it has reached a supercooled state, nucleation crystallization is performed. At this time, the presence of a large number of nucleation sources facilitates the rapid nucleation of the molten silicon material.
  • the degree of subcooling is controlled to be -1K to -30K during nucleation crystallization.
  • the degree of subcooling is low, the heat dissipation is slow, and the (111) plane can be fully developed.
  • the degree of supercooling is high, the direction of (110X112) grows fast and the heat dissipation is good.
  • a high degree of subcooling is advantageous for forming a crystal orientation which is dominant at (110X112), and since the grain boundaries are atomic staggered regions, dislocation slips to the grain boundary to be absorbed. Appropriate grain boundaries can prevent the proliferation and propagation of dislocations, which reduces the overall dislocation of the silicon ingot, thereby improving the conversion efficiency of crystalline silicon.
  • the method for preparing the polycrystalline silicon ingot includes:
  • microcrystalline nucleation layer is a non-silicon material nucleation source layer
  • the microcrystalline nucleation layer refers to a layer of material that provides microcrystalline or near microcrystalline nucleation sites.
  • microcrystalline silicide material and/or the amorphous silicide material are laid in a random manner without artificial arrangement, and the size of the microcrystalline silicide material and/or the amorphous silicide material is not limited.
  • the source and shape of the microcrystalline silicide material and/or the amorphous silicide material are not limited.
  • the microcrystalline silicide material and/or the amorphous silicide material have a purity of 3 ⁇ or more.
  • the microcrystalline silicide material and/or the amorphous silicide material has a melting point higher than a melting point of silicon.
  • Silicide material When the melting point of the microcrystalline silicide material or the amorphous silicide material is higher than the melting point of silicon, the microcrystalline nucleation layer silicide does not melt during heating, which does not introduce impurities into the silicon melt, thereby effectively ensuring Silicon ingot quality.
  • the microcrystalline silicide material is a glass ceramic or a microcrystalline ceramic.
  • the amorphous silicide material is amorphous glass or fused silica.
  • the microcrystalline silicide material and/or the amorphous silicide material is in the form of a rod, a block, a sheet, a strip or a pellet.
  • the thickness of the microcrystalline nucleation layer that is, the first height value is not limited, and may be determined according to actual conditions.
  • the first height value is from l to 150 mm. More preferably, the first height value is 5 to 150 mm. Further preferably, the first height value is 5 to 30 mm.
  • the microcrystalline nucleation layer is a microcrystalline silicide material or an amorphous silicide material having a melting point higher than the melting point of silicon or a mixture of the two, since the melting point is higher than that of silicon, silicide does not occur during the ingot casting process. Melting, so to avoid unnecessary waste, the thickness of the laying can be smaller.
  • the first height value is 0.01 to 30 mm. More preferably, when the microcrystalline nucleation layer is a microcrystalline silicide material or an amorphous silicide material having a melting point higher than a melting point of silicon, the first height value is 0.1 to 1 mm.
  • the finger according to the present invention refers to a container in which a polycrystalline silicon ingot is grown, and its shape and kind are not limited.
  • Step (2) filling a silicon material above the microcrystalline nucleation layer, heating to melt the silicon material to form a silicon melt, and the solid-liquid interface formed after the silicon material is completely melted is just in or deep into the crystallite In the nucleation layer, the thermal field is adjusted to form a supercooled state, and the silicon melt starts to grow on the basis of the microcrystalline nucleation layer.
  • the solid-liquid interface formed is just in the microcrystalline nucleation layer, and the thermal field is adjusted to form a supercooled state, so that the silicon melt is The crystal growth begins on the basis of the microcrystalline nucleation layer.
  • "just in the case of a microcrystalline nucleation layer” means that the solid-liquid interface in which the silicon melt melts is equal to the first height value from the bottom of the crucible.
  • the silicon material is melted at a temperature of 1500 to 1560 °C. Therefore, if the microcrystalline nucleation layer is a microcrystalline silicide material or an amorphous silicide material having a melting point lower than or equal to the melting point of silicon, the ingot is also melted during the ingot process, so it is necessary to detect the position of the solid solution interface of the silicon melt.
  • the thermal field is adjusted to allow it to nucleate the crystal.
  • the position of the solid solution interface where the silicon melt melts is detected every 0.2 to 1 h during the melting phase of the silicon material.
  • the position of the solid-liquid interface in which the silicon melt is melted is detected using a quartz rod.
  • the position of the solid-liquid interface in which the silicon melt melts is detected once every 0.5 to 1 h in the early stage of the melting phase of the silicon material.
  • the position of the solid-liquid interface where the silicon melt melts is detected every 0.2 to 0.5 h later in the melting stage of the silicon material.
  • the ingot process When the microcrystalline silicide material or the amorphous silicide material is a silicide having a melting point higher than the melting point of silicon, the ingot process generally does not melt, so it is not necessary to detect the position of the solid-liquid interface, and only the silicon material is completely melted, and then the process begins. Adjust the thermal field to nucleate the crystal.
  • the operation of adjusting the thermal field is to adjust the heating power to cool down, and the temperature drop is 2 ⁇ 30K/min.
  • the heating power of the heating device is lowered or the heating device is directly turned off, or the heat dissipating device is turned on, so that the thermal field of the silicon ingot growth reaches a supercooled state, and in the supercooled state, crystal growth is based on the microcrystalline core, and the crystal growth is performed.
  • the temperature inside the control crucible gradually rises in a direction perpendicular to the bottom of the crucible to form a temperature gradient.
  • each short-range order is equivalent to a small crystallite, which can be used as a crystallite of the long crystal.
  • the silicon material melts the silicon melt and the crystallite
  • the microcrystalline material or the amorphous material of the nucleation layer is in contact; when the temperature is further lowered, the silicon melt is grown on the microcrystalline material or the amorphous material. Due to the presence of microcrystals or a large number of microcrystalline nuclei close to the crystallites in the microcrystalline material or the amorphous material, the silicon melt grows a large number of fine crystal grains under the action of these microcrystalline nuclei. After subsequent optimization and elimination of growth, crystals with fine, uniform, and low dislocation density are obtained.
  • Step (3) After all the silicon melt is crystallized, it is annealed and cooled to obtain a polycrystalline silicon ingot.
  • the polycrystalline silicon ingot grows a large number of fine crystal grains by using the microcrystalline core, these fine crystal grains have a similar "necking" effect, and dislocations are eliminated through the grain boundaries. At the same time, it has a dominant crystal orientation. On the basis of this, it can be selected and crystallized to form crystals with favorable crystal orientation. Therefore, it can prevent the proliferation of dislocations and obtain high-quality polycrystalline silicon ingots. Since the microcrystalline nucleation layer is laid on the bottom of the crucible, a fine nucleation point is uniformly distributed, so that crystals with finer crystal grains and more uniform grain size can be obtained, and crystal defects are less proliferated slowly, thereby photoelectric conversion. higher efficiency.
  • the present invention provides a polycrystalline silicon ingot which is produced in accordance with the aforementioned method for producing a polycrystalline silicon ingot.
  • the polycrystalline silicon ingot has a low dislocation density and few defects.
  • the present invention provides a polycrystalline silicon wafer obtained by subjecting the polycrystalline silicon ingot to a raw material by chip-slice-cleaning.
  • Figure 1 is a schematic view showing the charging of Embodiment 1 of the present invention.
  • Figure 2 is a side view of Figure 1 of the present invention
  • Figure 3 is a plan view of Figure 1 of the present invention
  • Figure 4 is a schematic view of a porous material of the present invention.
  • Figure 5 is a diagram showing the result of detecting a bottom dislocation of a polycrystalline silicon ingot according to Embodiment 1 of the present invention.
  • Figure 6 is a view showing the result of detecting the position of the polycrystalline silicon ingot in the first embodiment of the present invention
  • FIG. 7 is a schematic view showing a preparation process of Embodiment 5 of the present invention
  • Figure 8 is a photograph showing the blocking effect of the grain boundary on the dislocation of the polycrystalline silicon ingot obtained in Example 5 by the photoluminescence silicon wafer detecting system;
  • Figure 9 is a photographic view of a polycrystalline silicon ingot grown with a nucleation layer
  • Figure 10 is a photo of a conventional polycrystalline silicon ingot
  • Figure 11 is a photograph showing the head of a polycrystalline silicon ingot obtained in Example 5 of the present invention.
  • Figure 12 is a photograph showing the tail portion of a polycrystalline silicon ingot obtained in Example 5 of the present invention.
  • Figure 13 is a photograph of a head of a polycrystalline silicon ingot prepared in accordance with a comparative example of the present invention.
  • Figure 14 is a photograph of the tail of a polycrystalline silicon ingot prepared in accordance with a comparative example of the present invention. detailed description
  • a method for preparing a polycrystalline silicon ingot comprising:
  • FIGS. 1 to 3 are schematic diagrams of the charging of the embodiment.
  • 1 is ⁇
  • 2 is graphite shielding
  • 3 is nitriding.
  • Silicon porous material, 4 is silicon material.
  • the above-mentioned silicon-containing crucible is placed in an ingot furnace, the ingot casting process is started, vacuum is applied, and then heated, heated to a melting point of silicon, and the silicon material is slowly melted to form a silicon melt. After the silicon material is completely melted, the insulating cage is slowly opened and the temperature is lowered, so that the temperature of the silicon melt is lowered to form a supercooled state, and the nucleation is crystallized. Wait until the silicon ingot is solidified. After annealing and cooling, a polycrystalline silicon ingot is obtained.
  • the polycrystalline silicon ingot obtained above is cooled, the polycrystalline silicon chunks are obtained by opening, and the polycrystalline silicon wafer is obtained by slicing, and a solar cell is produced by a screen printing process.
  • the obtained polycrystalline silicon ingot was subjected to dislocation observation using an optical microscope (magnification 200 times), and the detection result was as follows: the average dislocation density at the bottom of the silicon ingot was 2.57 10 4 (pieces/cm 2 ), as shown in Fig. 5 is the bottom position of the silicon ingot.
  • Fig. 6 is a diagram showing the result of the detection of the position of the silicon ingot.
  • the photoelectric conversion efficiency of the German halm cell sheet measuring instrument was measured.
  • the photoelectric conversion efficiency of the solar cell was 17.4%.
  • a method for preparing a polycrystalline silicon ingot comprising:
  • a quartz crucible is used, after spraying a layer of silicon nitride on the inner wall of the crucible. Place 25 square SiC porous materials with a size of 155 X 155mm on the bottom of the crucible. After the paving is completed, the silicon carbide is filled on the porous silicon carbide material until it is completely loaded.
  • the above-mentioned silicon-containing crucible is placed in an ingot furnace, the ingot casting process is started, vacuum is applied, and then heated, heated to a melting point of silicon, and the silicon material is slowly melted to form a silicon melt. After the silicon material is completely melted, the insulating cage is slowly opened and the temperature is lowered, so that the temperature of the silicon melt is lowered to form a supercooled state, and the nucleation is crystallized.
  • the polycrystalline silicon ingot obtained above is cooled, the polycrystalline silicon chunks are obtained by opening, and the polycrystalline silicon wafer is obtained by slicing, and a solar cell is produced by a screen printing process.
  • the photoelectric conversion efficiency of the German halm company was measured. As a result of the measurement, the photoelectric conversion efficiency of the solar cell was 17.5%.
  • a method for preparing a polycrystalline silicon ingot comprising:
  • a quartz crucible is used, after spraying a layer of silicon nitride on the inner wall of the crucible. Place 25 square quartz porous materials with a size of 155 x l55mm on the bottom of the crucible. After the paving is completed, the silicon porous material is filled with silicon material until it is completely loaded.
  • the above-mentioned silicon-containing crucible is placed in an ingot furnace, the ingot casting process is started, vacuum is applied, and then heated, heated to a melting point of silicon, and the silicon material is slowly melted to form a silicon melt. After the silicon material is completely melted, the insulating cage is slowly opened and the temperature is lowered, so that the temperature of the silicon melt is lowered to form a supercooled state, and the nucleation is crystallized.
  • the polycrystalline silicon ingot obtained above is cooled, the polycrystalline silicon chunks are obtained by opening, and the polycrystalline silicon wafer is obtained by slicing, and a solar cell is produced by a screen printing process.
  • the obtained polycrystalline silicon ingot was subjected to dislocation observation using an optical microscope (magnification 200 times), and the detection result was as follows: the average dislocation density at the bottom of the silicon ingot was 2.03 X 10 4 (pieces/cm 2 ); the average position of the silicon ingot head The error density was 3.10 X 10 4 (pieces/cm 2 ).
  • the photoelectric conversion efficiency of the German halm cell sheet measuring instrument was measured.
  • the photoelectric conversion efficiency of the solar cell was 17.58%.
  • a method for preparing a polycrystalline silicon ingot comprising:
  • a quartz crucible is used, after spraying a layer of silicon nitride on the inner wall of the crucible.
  • a layer of polycrystalline scrap having a thickness of 1 cm was placed on the bottom of the crucible, and 25 square silicon nitride porous materials having a size of 155 x l 55 mm were laid on the polycrystalline scrap.
  • the silicon nitride material is filled on the silicon nitride porous material until it is completely loaded.
  • the above-mentioned silicon-containing crucible is placed in an ingot furnace, the ingot casting process is started, vacuum is applied, and then heated, heated to a melting point of silicon, and the silicon material is slowly melted to form a silicon melt.
  • the insulating cage is slowly opened and the temperature is lowered, so that the temperature of the silicon melt is lowered to form a supercooled state, and the nucleation is crystallized.
  • the polycrystalline silicon ingot obtained above is cooled, the polycrystalline silicon chunks are obtained by opening, and the polycrystalline silicon wafer is obtained by slicing, and a solar cell is produced by a screen printing process.
  • the obtained polycrystalline silicon ingot was subjected to dislocation observation using an optical microscope (magnification 200 times), and the detection result was as follows: the average dislocation density at the bottom of the silicon ingot was 2.08 X 10 4 (pieces/cm 2 ); the average position of the silicon ingot head The error density was 2.88 X 10 4 (pieces/cm 2 ).
  • the photoelectric conversion efficiency of the German halm cell sheet measuring instrument was measured.
  • the measurement result shows that the photoelectric conversion efficiency of the solar cell is 17.62%.
  • the preparation method of the polycrystalline silicon ingot includes the following steps:
  • the nucleation source is arranged at the bottom of the crucible: a mixture of silicon powder and silicon nitride powder is 300 g in total, wherein the silicon powder and the silicon nitride powder have a mass ratio of 6:4, and 500 ml of alcohol is applied to the bottom of the crucible.
  • the coating was baked in an 800 degree oven for 2 hours.
  • the particle size of the silicon powder is 10um, and the particle size of the silicon nitride powder is 0.5 ⁇ 50.
  • the silicon material in the molten state is disposed on the nucleation source layer: 450 to 800 kg of solid silicon material is loaded above the nucleation source layer, and the crucible is heated to 1560 ° C to melt the solid silicon material, at this time, the molten state
  • the silicon material is disposed on the surface of the nucleation source layer.
  • Figure 7 is a schematic view of the preparation process of the present embodiment.
  • 1 is the ⁇ body
  • 2 is the nucleation source layer
  • 3 It is a silicon nitride layer provided on the sidewall of the crucible
  • 4 is a solid silicon material.
  • the heat insulating cage controls the bottom temperature to be 1380 ° C, so that the silicon melt reaches a supercooled state and nucleates by nucleation to obtain a polycrystalline silicon ingot.
  • Fig. 8 is a photograph showing the prevention of the dislocation of the grain boundary of the polycrystalline silicon ingot obtained in the present embodiment by the photoluminescence silicon wafer detecting system. As shown in Fig. 8, the dislocation slip at the grain boundary is significantly suppressed, and a clear dislocation-free region and a dislocation region are formed on both sides of the grain boundary.
  • the dislocation density of the polycrystalline silicon ingot obtained in this embodiment is 1.6 X 10 ⁇ 1.8 X 10 3 /cm 2 , and the minority carrier lifetime is 24 ⁇ sec (us ).
  • the polycrystalline silicon wafer produced by using the polycrystalline silicon ingot obtained in the present embodiment is suitable for the preparation of a solar cell, and the solar cell conversion efficiency is 17.8%.
  • the preparation method of the polycrystalline silicon ingot includes the following steps:
  • the nucleation source is arranged at the bottom of the crucible: a mixture of silicon carbide and silicon nitride powder is 200 g in total, wherein the silicon carbide and silicon nitride powder have a mass ratio of 8:2, and 500 ml of water is used, and a compressed air spray gun is used for spraying. Bake at the bottom of the crucible for 2 hours in a 1000 degree oven.
  • the silicon carbide and silicon nitride powders have a particle size of 20 ⁇ m.
  • the silicon material in the molten state is disposed on the nucleation source layer: 450 to 800 kg of solid silicon material is loaded above the nucleation source layer, and the crucible is heated to 1560 ° C to melt the solid silicon material, at this time, the molten state
  • the silicon material is disposed on the surface of the nucleation source layer.
  • the heat insulating cage controls the bottom temperature to be 1300 ° C, so that the silicon melt reaches a supercooled state and nucleates by nucleation to obtain a polycrystalline silicon ingot.
  • the dislocation density of the polycrystalline silicon ingot obtained in this example is 7.2 10 ⁇ 7.8 X 10 3 /cm 2 , and the minority carrier lifetime is 20 ⁇ sec ( us ).
  • the polycrystalline silicon wafer obtained by using the polycrystalline silicon ingot obtained in the present embodiment is suitable for preparing a solar cell, and the solar cell conversion efficiency obtained is 17.6%.
  • the preparation method of the polycrystalline silicon ingot includes the following steps:
  • the nucleation source is arranged at the bottom of the crucible: a mixture of carbon powder and silicon nitride powder is 300 g in total, wherein the silicon carbide and silicon nitride powder have a mass ratio of 6:4, and 500 ml of alcohol is applied to the bottom of the crucible.
  • the coating was baked in an 800 degree oven for 2 hours.
  • the particle size of the toner is 20 ⁇ m, and the particle size of the silicon nitride powder is 5 ⁇ m.
  • the silicon material in a molten state is disposed on the nucleation source layer: heating 450 to 800 kg of the solid silicon material in another crucible, heating to 1560 ° C, preparing a molten silicon material, and melting the silicon material. It is cast into a crucible provided with a nucleation source layer, and at this time, a molten silicon material is disposed on the surface of the nucleation source layer.
  • the heat insulating cage controls the bottom temperature to be 1350 ° C, so that the silicon melt reaches a supercooled state and nucleates by nucleation to obtain a polycrystalline silicon ingot.
  • the dislocation density of the polycrystalline silicon ingot obtained in this embodiment is 1.8 X 10 4 to 2.0 X 10 4 /cm 2 , and the minority lifetime For 13 microseconds (us)
  • the polycrystalline silicon wafer prepared by using the polycrystalline silicon ingot prepared in this embodiment is suitable for preparing a solar cell, and the conversion efficiency of the obtained solar cell is 17.4%.
  • the preparation method of the polycrystalline silicon ingot includes the following steps:
  • the nucleation source is arranged at the bottom of the crucible: a mixture of quartz powder and silicon nitride powder is 300 g in total, wherein the silicon carbide and the silicon nitride powder have a mass ratio of 6:4, and 500 ml of alcohol is applied to the bottom of the crucible.
  • the coating was baked in an 800 degree oven for 2 hours.
  • the particle size of the quartz powder is lcm, and the particle size of the silicon nitride powder is 10
  • the silicon material in the molten state is disposed on the nucleation source layer: 450 to 800 kg of solid silicon material is loaded above the nucleation source layer, and the crucible is heated to 1560 ° C to melt the solid silicon material, at this time, the molten state
  • the silicon material is disposed on the surface of the nucleation source layer.
  • the heat insulating cage controls the bottom temperature to be 1350 ° C, so that the silicon melt reaches a supercooled state and nucleates by nucleation to obtain a polycrystalline silicon ingot.
  • the dislocation density of the polycrystalline silicon ingot obtained in this embodiment is 3.0 X 10 4 to 3.5 X 10 4 /cm 2 , and the minority carrier lifetime is 12 microseconds ( us )
  • the polycrystalline silicon wafer obtained by using the polycrystalline silicon ingot prepared in this embodiment is suitable for preparing a solar cell, and the conversion efficiency of the obtained solar cell is 17.3%.
  • Example 9 (1) arranging a nucleation source at the bottom of the crucible to form a nucleation source layer
  • the nucleation source is arranged at the bottom of the crucible: a mixture of silicon powder and quartz silicon powder is directly placed at the bottom of the crucible, wherein the silicon powder and the quartz silica powder have a mass ratio of 8:2.
  • the silicon material in the molten state is disposed on the nucleation source layer: 450 to 800 kg of solid silicon material is loaded above the nucleation source layer, and the crucible is heated to 1560 ° C to melt the solid silicon material, at this time, the molten state
  • the silicon material is disposed on the surface of the nucleation source layer.
  • the heat insulating cage controls the bottom temperature to be 1360 ° C, so that the silicon melt reaches a supercooled state and nucleates by nucleation to obtain a polycrystalline silicon ingot.
  • the dislocation density of the polycrystalline silicon ingot obtained in this example was 3.0 X 10 to 5.0 X 10 3 /cm 2 , and the minority carrier lifetime was 19 ⁇ sec (us).
  • the polycrystalline silicon wafer obtained by using the polycrystalline silicon ingot obtained in the present embodiment is suitable for preparing a solar cell, and the solar cell conversion efficiency obtained is 17.7%.
  • the nucleation source is arranged at the bottom of the crucible: a mixture of silicon powder, silicon carbide powder and silicon nitride powder is 250 g, wherein the silicon powder: silicon carbide powder: silicon nitride powder has a mass ratio of 4:2: 4.
  • the silicon powder: silicon carbide powder: silicon nitride powder has a mass ratio of 4:2: 4.
  • 400ml of alcohol apply a coating on the bottom of the crucible and bake in a 600 degree oven for 2 hours.
  • the particle size of the silicon powder is lmm
  • the particle size of the silicon carbide powder is 0.5 mm
  • the particle size of the silicon nitride powder is 0.5 to 50 um.
  • the silicon material in a molten state is disposed on the nucleation source layer: loading solid silicon material above the nucleation source layer 450 to 800 kg, the crucible is heated to 1560 ° C to melt the solid silicon material, and at this time, the molten silicon material is placed on the surface of the nucleation source layer.
  • the heat insulating cage controls the bottom temperature to be 1360 ° C, so that the silicon melt reaches a supercooled state and nucleates by nucleation to obtain a polycrystalline silicon ingot.
  • the dislocation density of the polycrystalline silicon ingot obtained in this example was 5.5 X 10 4 to 8.0 X 10 4 /cm 2 , and the minority carrier lifetime was 11 ⁇ sec (us ).
  • the polycrystalline silicon wafer obtained by using the polycrystalline silicon ingot obtained in the present embodiment is suitable for the preparation of a solar cell, and the solar cell conversion efficiency is 17.2%.
  • the nucleation source is arranged at the bottom of the crucible: 200 g of quartz powder is directly laid on the silicon nitride coating originally coated on the bottom of the crucible.
  • the quartz powder has a particle size of 0.5 to 50 ⁇ m.
  • the silicon material in the molten state is disposed on the nucleation source layer: 450 to 800 kg of solid silicon material is loaded above the nucleation source layer, and the crucible is heated to 1560 ° C to melt the solid silicon material, at this time, the molten state
  • the silicon material is disposed on the surface of the nucleation source layer.
  • the heat insulating cage controls the bottom temperature to be 1360 ° C, so that the silicon melt reaches a supercooled state and nucleates by nucleation to obtain a polycrystalline silicon ingot.
  • the dislocation density of the polycrystalline silicon ingot obtained in this embodiment is 4.6 X 10 3 ⁇ 6.8 X 10 3 /cm 2 , and the minority lifetime It is 20 microseconds (us).
  • the polycrystalline silicon wafer produced by using the polycrystalline silicon ingot obtained in the present embodiment is suitable for the preparation of a solar cell, and the solar cell conversion efficiency is 17.8%.
  • Comparative test The silicon material was placed in a silicon nitride coated crucible, heated to 1560 ° C for melting, and then the insulating cage was opened, so that the bottom began to cool. After the crystal growth is completed, it enters the annealing cooling stage. The polycrystalline silicon ingot is obtained after being completely cooled.
  • Fig. 9 is a photographic view of a polycrystalline silicon ingot grown with a nucleation layer
  • Fig. 10 is a photographic view of a conventional polycrystalline silicon ingot. It can be seen from Fig. 9 and Fig. 10 that the polycrystalline silicon ingot grown by the nucleation layer has less dislocations, fine and uniform crystal grains, and straight growth direction, while ordinary polycrystalline silicon ingots have high dislocation density and uneven grain size (generally more Bright indicates that the fewer the dislocations, the higher the efficiency. The black area is the area with high dislocations).
  • Figure 11 is a photograph of a head of a polycrystalline silicon ingot obtained in Example 5 of the present invention
  • Figure 12 is a photograph of a tail of a polycrystalline silicon ingot obtained in Example 5 of the present invention
  • Figure 13 is a head of a polycrystalline silicon ingot obtained in a comparative example of the present invention
  • Photograph, Figure 14 is a photograph of a tail of a polycrystalline silicon ingot prepared in accordance with a comparative example of the present invention.
  • the crystal grains of the polycrystalline silicon ingot obtained by the present invention are 0.5 to 8 mm, and the particle size distribution is narrow (80% is concentrated in 2 to 5 mm), and the size is uniform and regular.
  • the upper grain size is 0.5 ⁇ 4 cm, the particle size distribution is narrow (90% concentrated in l ⁇ 3cm), the size is uniform, the rule is high, and the circularity is high.
  • the dislocation density is low (10 5 /cm 2 ), with no obvious dendrites and twins.
  • the dislocation density of the polycrystalline silicon ingot prepared by setting the nucleation source layer is less than 10 5 /cm 2 , and the minority carrier lifetime is 10 to 25 us.
  • the dislocation density of the silicon wafer obtained by the conventional method is 10 5 to 10 6 cm 2 , and the lifetime of the minority carrier is 5 to 10 ⁇ s.
  • the polycrystalline silicon wafer obtained by using the obtained polycrystalline silicon ingot is suitable for preparing a solar cell, and the conversion efficiency of the obtained solar cell is 17.1 to 17.8%, and the conversion efficiency of the solar cell obtained by the conventional polycrystalline silicon wafer is 16.5 to 17.0%.
  • the preparation method of the polycrystalline silicon ingot includes the following steps:
  • the silicon melt is crystallized, it is annealed to obtain a polycrystalline silicon ingot.
  • the polycrystalline silicon ingot obtained above is cooled, the polycrystalline silicon ingot is obtained by opening, and the polycrystalline silicon wafer is obtained after slicing and cleaning, and the polycrystalline silicon wafer is used as a raw material to form a solar cell by a screen printing process.
  • the obtained polycrystalline silicon ingot was subjected to dislocation observation using an optical microscope (magnification of 200 times), and the detection result was 5.2 x 10 4 /cm 2 .
  • the photoelectric conversion efficiency of the German halm cell sheet measuring instrument was measured. As a result of the measurement, the photoelectric conversion efficiency of the solar cell was 17.5%.
  • the preparation method of the polycrystalline silicon ingot includes the following steps:
  • microcrystalline glass at the bottom of the crucible to form a microcrystalline nucleation layer; then filling the microcrystalline nucleation layer with silicon material until it is completely loaded; the thickness of the microcrystalline nucleation layer is 0.5 mm;
  • the polycrystalline silicon ingot obtained above is cooled, the polycrystalline silicon ingot is obtained by opening, and the polycrystalline silicon wafer is obtained by slicing-cleaning, and the solar cell is fabricated by using a screen printing process using the polycrystalline silicon wafer as a raw material.
  • the obtained polycrystalline silicon ingot was subjected to dislocation observation using an optical microscope (magnification of 200 times), and the detection result was 8.2 x 10 4 /cm 2 .
  • the photoelectric conversion efficiency of the German halm cell sheet measuring instrument was measured. As a result of the measurement, the photoelectric conversion efficiency of the solar cell was 17.3%.
  • Example 14 The preparation method of the polycrystalline silicon ingot includes the following steps:

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Silicon Compounds (AREA)

Abstract

本发明公开了一种多晶硅锭的制备方法，该制备方法包括在坩埚底部设置非硅材质形核源层，在所述非硅材质形核源层上方填装硅料；加热使所述硅料熔化，调节所述坩埚内热场，使熔化的硅料在所述非硅材质形核源层基础上开始长晶；待全部结晶完后，经退火冷却得到多晶硅锭。采用该制备方法能使多晶硅锭得到良好的初始形核，降低多晶硅锭在生长过程中的位错繁殖。本发明还同时公开了一种通过该制备方法获得的多晶硅锭，以及以所述多晶硅锭为原料制得的多晶硅片。

Description

一种多晶硅锭及其制备方法和多晶硅片 本申请要求于 2012年 4月 1日提交中国专利局的申请号为 201210096209.3 , 其发明名称为 "一种多晶硅锭及其制备方法和多晶硅片" 的中国专利申请的优 先权， 其全部内容通过引用结合在本申请中； 本申请要求于 2012年 4月 1 曰提 交中国专利局的申请号为 201210096291.X, 其发明名称为 "多晶硅锭及其制备 方法、 多晶硅片和多晶硅铸锭用坩埚" 的中国专利申请、 于 2013年 1月 29 日 提交中国专利局的申请号为 201310033073.6, 其发明名称为 "多晶硅锭及其制 备方法和多晶硅片" 的中国专利申请的优先权， 其部分内容通过引用结合在本 申请中。 技术领域
本发明涉及半导体制造领域， 尤其涉及一种多晶硅锭及其制备方法和多晶 硅片。
背景技术
近年来， 太阳能作为一种新兴的可再生绿色能源已经成为了人们开发和研 究的热点。 伴随着太阳能电池业的快速发展， 成本低且适于规模化生产的多晶 硅成为行业内最主要的光伏材料之一， 并逐步取代传统的直拉单晶硅在太阳能 电池材料市场中的主导地位。
目前， 多晶硅锭的制备方法主要为采用 GT Solar所提供的定向凝固系统法 (筒称 DSS ) 炉晶体生长技术， 该方法通常包括加热、 熔化、 凝固长晶、 退火 和冷却等步骤。 在凝固长晶过程中， 伴随着坩埚底部的持续冷却， 熔融状态的 硅料自发形成随机形核并且随机形核逐渐生长。 但由于初始形核没有得到控制， 形核过程中容易产生位错， 导致晶向杂乱， 晶粒不均勾， 因此通过该方法制备 得到的多晶硅锭质量较低。 利用该多晶硅锭制得的太阳能电池的光电转换效率 低。 因此， 为了制得位错密度低、 缺陷少的高质量多晶硅锭， 一种能有效获得 良好初始形核的多晶硅锭铸造方法变得很重要。
发明内容
为了解决上述技术问题，本发明旨在提供一种多晶硅锭的制备方法，该制备 方法能够使多晶硅锭获得良好的初始形核， 降低多晶硅锭在生长过程中的位错 繁殖， 得到高质量多晶硅锭。 本发明同时提供了通过该制备方法获得的高质量 的多晶硅锭， 以及以所述多晶硅锭为原料制得的多晶硅片。
第一方面， 本发明提供了一种多晶硅锭的制备方法， 包括：
在坩埚底部设置非硅材质形核源层， 在所述非硅材质形核源层上方填装硅 料； 加热使所述硅料熔化， 调节所述坩埚内热场， 使熔化的硅料在所述非硅材 质形核源层基础上开始长晶； 待全部结晶完后， 经退火冷却得到多晶硅锭。
本发明提供的多晶硅锭的制备方法， 硅熔体在非硅材质形核源层上能形成 多个均匀分布的形核源， 从而使多晶硅锭获得良好的初始形核， 进而生长出具 有优势晶向的晶体。
优选地， 所述多晶硅锭的制备方法， 包括：
在坩埚内壁涂上氮化硅涂层后， 在所述坩埚底部铺垫一层多孔材料形成非 硅材质形核源层， 然后在所述多孔材料上填装硅料；
加热所述填装有硅料的坩埚， 使所述硅料熔化形成硅熔体， 调整热场， 使 硅熔体开始形核结晶；
待硅熔体界面向远离所述坩埚底部的方向移动， 定向结晶凝固完后， 经退 火冷却得到多晶硅锭。 优选地， 多孔材料为熔点大于硅的熔点且高温下不与硅发生反应的材质。 优选地， 多孔材料为氮化硅、 碳化硅或石英。
优选地， 多孔材料的孔径为 0.1cm~5cm。
优选地， 多孔材料的厚度为 0.1~2cm。
优选地， 多孔材料的尺寸大小为 10 X 10mm~155 155mm。 由于氮化硅、 碳化硅或石英等多孔材料具有多个孔洞， 在硅料熔化阶段， 硅料熔化形成的硅熔体将填充在孔洞中， 在初始形核阶段， 在过冷状态下， 硅熔体在孔洞中进行自由形核结晶， 此种情况下的形核结晶过程， 不是在一 个大平面范围内完成， 而是在无数的小孔洞中进行， 因而能控制大量枝晶的 出现和生长。 在形核阶段， 控制温度使填充在孔洞中的硅熔体先达到过冷状 态， 从而使多晶硅锭获得良好的初始形核， 进而生长出具有优势晶向的晶体。 优选地， 在所述填装硅料之前还包括， 在所述多孔材料上方铺垫一层硅碎 料。
优选地， 硅碎料为单晶硅碎料、 多晶硅碎料和非晶体硅碎料中的一种或几 种。 优选地， 硅碎料的尺寸大小为 0.1cm~10cm。
优选地， 硅碎料铺设厚度为 0.5cm~5cm。
硅碎料铺垫在坩埚底部为无序排列， 碎料层形成一个支架结构， 该支架结 构具有无数的孔洞， 在硅料熔化阶段， 硅料熔化形成的硅熔体将填充在孔洞中， 在初始形核阶段， 在过冷状态下， 在硅碎料层面上形成多个均勾分布的形核源， 从而使多晶硅锭获得良好的初始形核， 进而生长出具有优势晶向的晶体。 具体 地， 控制温度使处于硅熔体与未熔化的硅料所形成的固液界面的硅熔体及填充 在孔洞中的硅熔体先达到过冷状态， 优先形核结晶， 随后硅熔体界面向远离坩 埚底部的方向移动， 硅熔体结晶凝固。 多晶硅锭的初始形核得到良好控制， 从 而生长出有益晶向占主导地位的晶体， 因此可以防止位错的大量增殖， 得到高 质量多晶娃键。
此外， 坩埚内壁上氮化硅层的设置， 可以有效防止坩埚底部的杂质进入晶 体中， 从而提高多晶硅锭的质量。
优选地， 所述多晶硅锭的制备方法， 包括：
( 1 )在坩埚底部设置形核源， 形成形核源层； 所述形核源选自与硅料的晶 格接近的硅系化合物和 /或与硅料反应生成硅系化合物的材料， 或硅粉、 与硅料 的晶格接近的硅系化合物和与硅料反应生成硅系化合物的材料中的一种或几种 与氮化硅的混合物；
( 2 )在所述形核源层上设置熔融状态的硅料； 所述在形核源层上设置熔融 状态的硅料为： 在所述形核源层上方装载固体硅料， 对所述坩埚进行加热使得 所述硅料熔融， 此时， 所述熔融状态的硅料设置于所述形核源层表面； 或在另 外一个坩埚内加热固体硅料， 制得熔融状态的硅料， 将所述熔融状态的硅料浇 铸至所述铺设有形核源层的坩埚内， 此时， 所述熔融状态的硅料设置于所述形 核源层表面；
( 3 )控制所述坩埚内的温度沿垂直与所述坩埚底部向上的方向逐渐上升形 成温度梯度， 使得所述熔融状态的硅料利用所述形核源形核结晶， 制得多晶硅 键。
其中， 步骤（1 ) 中设置形核源的形式不限。 优选地， 设置形核源为将形核 源涂覆设置在坩埚底部， 或者是将形核源直接铺设在坩埚底部。
优选地， 形核源的粒径为 0.1um~lcm。
优选地， 与硅料的晶格接近的硅系化合物为碳化硅粉或石英粉。
优选地， 与硅料反应生成硅系化合物的材料为碳粉。 本发明所述的坩埚指容置多晶硅锭生长的容器， 其形状和种类不限。
步骤（3 ) 中， 控制坩埚内的热场为对熔融状态的硅料进行冷却， 使其达到 过冷状态后进行形核结晶。 此时， 大量的形核源的存在有利于熔融状态的硅料 迅速形核。
优选地， 形核结晶过程中控制过冷度为 -1K~-30K。 当过冷度低的时候， 散 热较慢， 此时（111 )面能够充分发育， 而高过冷度时， 由于 (110X112)的方向生 长快， 散热性好。 高的过冷度有利于形成以（110X112)占优的晶向， 同时由于晶 界为原子错排区， 位错滑移到晶界处被吸收。 适量的晶界能够阻止位错的增殖 扩展， 使得硅锭的整体位错减少， 从而提高晶体硅的转换效率。
优选地， 所述多晶硅锭的制备方法， 包括：
( 1 )在坩埚底部铺设微晶形核层， 所述微晶形核层为微晶硅化物材料和 / 或无定形硅化物材料； 所述微晶形核层的厚度为第一高度值； 所述微晶形核层 为非硅材质形核源层；
( 2 )在所述微晶形核层上方填装硅料， 加热使所述硅料熔化形成硅熔体， 待所述硅料完全熔化后形成的固液界面刚好处在或深入微晶形核层时， 调节热 场形成过冷状态， 使所述硅熔体在微晶形核层基础上开始长晶；
( 3 )待全部硅熔体结晶完后， 经退火冷却得到多晶硅锭。
所述微晶形核层是指提供微晶或接近微晶形核点的材料层。
所述微晶硅化物材料和 /或无定形硅化物材料的铺设方式为随意铺设， 无需 人为地进行排布， 所述微晶硅化物材料和 /或无定形硅化物材料的尺寸不限。 此 外微晶硅化物材料和 /或无定形硅化物材料的来源、 形状不限。 所述微晶硅化物 材料和 /或无定形硅化物材料的纯度为 3Ν以上。
优选地， 所述微晶硅化物材料和 /或无定形硅化物材料为熔点高于硅熔点的 硅化物材料。 当微晶硅化物材料或无定形硅化物材料熔点高于硅熔点时， 加热 过程中， 微晶形核层硅化物不会熔化， 这就不会使硅熔体中引入杂质， 从而能 有效保证硅锭质量。
优选地， 所述微晶硅化物材料为微晶玻璃或微晶陶瓷。
优选地， 所述无定形硅化物材料为无定形玻璃或熔融石英。
优选地， 所述微晶硅化物材料和 /或无定形硅化物材料为棒状、 块状、 片状、 条状或颗粒状。
微晶形核层的厚度即第一高度值不限， 可根据实际情况确定。 优选地， 所 述第一高度值为 l~150mm。 更优选地， 所述第一高度值为 5~150mm。 进一步优 选地， 所述第一高度值为 5~30mm。
当所述微晶形核层为熔点高于硅熔点的微晶硅化物材料或无定形硅化物材 料或两者混合时， 由于其熔点比硅高， 因此在铸锭过程中， 硅化物不会熔化， 所以为避免不必要的浪费， 铺设厚度可小一点。 优选地， 当微晶形核层为熔点 高于硅熔点的微晶硅化物材料或无定形硅化物材料时， 所述第一高度值为 0.01~30mm。 更优选地， 当微晶形核层为熔点高于硅熔点的微晶硅化物材料或无 定形硅化物材料时， 所述第一高度值为 0.1~lmm。
本发明所述的坩埚指容置多晶硅锭生长的容器， 其形状和种类不限。
步骤（2 )在所述微晶形核层上方填装硅料， 加热使所述硅料熔化形成硅熔 体， 待所述硅料完全熔化后形成的固液界面刚好处在或深入微晶形核层时， 调 节热场形成过冷状态， 使所述硅熔体在微晶形核层基础上开始长晶。
优选地， 待所述硅料完全熔化， 所述硅化物不熔化时， 即形成的固液界面 刚好处在微晶形核层时， 调节热场形成过冷状态， 使所述硅熔体在微晶形核层 基础上开始长晶。 本发明中 "刚好处在微晶形核层时"， 是指所述硅熔体熔化的固液界面距所 述坩埚底部的高度等于第一高度值时。
通常， 硅料熔化的温度为 1500~1560°C。 因此， 如果微晶形核层为熔点低于 或等于硅熔点的微晶硅化物材料或无定形硅化物材料时， 铸锭过程中也会熔化， 因此需要探测其硅熔体固液界面位置， 待硅料刚好全部熔化或微晶形核层部分 熔化但未全部熔化时， 开始调节热场让其形核长晶。
优选地， 在硅料的熔化阶段， 每隔 0.2~lh, 探测一次所述硅熔体熔化的固 液界面的位置。
具体地， 采用石英棒探测所述硅熔体熔化的固液界面的位置。
优选地， 在硅料的熔化阶段前期， 每隔 0.5~lh, 探测一次所述硅熔体熔化 的固液界面的位置。
优选地， 在硅料的熔化阶段后期， 每隔 0.2~0.5h, 探测一次所述硅熔体熔化 的固液界面的位置。
而微晶硅化物材料或无定形硅化物材料为熔点高于硅熔点的硅化物时， 铸 锭过程中一般不熔化， 因此不需要探测固液界面位置， 只需要使得硅料全部熔 化， 便开始调节热场让其形核长晶。
优选地， 调节热场的操作为调节加热功率降温， 降温的幅度为 2~30K/min。 具体地， 降低加热装置的加热功率或直接关闭加热装置， 或打开热量散热 装置， 使硅锭生长的热场达到过冷状态， 在该过冷状态下以微晶核为基础长晶， 长晶过程中控制坩埚内的温度沿垂直与坩埚底部向上的方向逐渐上升形成温度 梯度。
由于微晶材料或无定形材料具有一定近程有序， 因此每个近程有序的范围 内都相当于一个小微晶， 可作为长晶的微晶核。 当硅料融化时， 硅熔体与微晶 形核层的微晶材料或无定形材料接触； 当进一步降低温度时， 硅熔体在微晶材 料或无定形材料上生长。 由于微晶材料或无定形材料中存在微晶或接近微晶的 大量的微晶核， 硅熔体在这些微晶核的作用下， 生长出大量的细小的晶粒。 经 过后续的择优和淘汰生长， 得到了晶粒细小， 均匀， 位错密度低的晶体。
步骤（3 )待全部硅熔体结晶完后， 经退火冷却得到多晶硅锭。
由于多晶硅锭利用微晶核生长出了大量细小晶粒， 这些细小晶粒产生类似 "缩颈" 的作用， 通过晶界排除位错。 同时具有优势晶向， 在此基础上经过择 优和生长淘汰可进而生长出有益晶向占主导地位的晶体， 因此可以防止位错的 大量增殖， 得到高质量多晶硅锭。 由于在坩埚底部铺设了微晶形核层， 提供了 均匀分布的细小的形核点， 因此可得到晶粒更细小且晶粒尺寸更均勾的晶体， 晶体缺陷更少增殖緩慢， 从而光电转换效率更高。
第二方面，本发明提供了一种多晶硅锭，所述多晶硅锭按照前述多晶硅锭的 制备方法制得。 所述多晶硅锭位错密度低、 缺陷少。
第三方面，本发明提供了一种多晶硅片，所述多晶硅片以前述多晶硅锭为原 料经开方 -切片 -清洗制得。 附图说明
图 1是本发明实施例 1的装料后示意图；
图 2是本发明图 1的侧视图； 图 3是本发明图 1的俯视图；
图 4是本发明多孔材料的示意图；
图 5是本发明实施例 1的多晶硅锭底部位错检测结果图；
图 6是本发明实施例 1的多晶硅锭头部位错检测结果图；
图 7为本发明实施例 5制备过程的示意图； 图 8为通过光致发光硅片检测系统观测实施例 5制得的多晶硅锭的晶界对位 错的阻止作用的照片；
图 9为带形核层生长出来的多晶硅锭的照片图；
图 10为普通多晶硅锭的照片图；
图 11为本发明实施例 5制得的多晶硅锭头部照片图；
图 12为本发明实施例 5制得的多晶硅锭尾部照片图；
图 13为本发明对比实施例制得的多晶硅锭头部照片图；
图 14为本发明对比实施例制得的多晶硅锭尾部照片图。 具体实施方式
下面将结合本发明实施例中的附图， 对本发明实施例中的技术方案进行清 楚、 完整地描述， 显然， 所描述的实施例仅仅是本发明一部分实施例， 而不是 全部的实施例。 基于本发明中的实施例， 本领域普通技术人员在没有作出创造 性劳动前提下所获得的所有其他实施例， 都属于本发明保护的范围。
实施例 1
一种多晶硅锭的制备方法， 包括：
采用石英坩埚， 在坩埚内壁喷涂一层氮化硅涂层后。 在坩埚底部铺垫 25块 尺寸为 155mm X 155mm的方形氮化硅多孔材料。 铺垫完后， 在氮化硅多孔材料 上填装硅料， 直到全部装完， 图 1~3为本实施例装料示意图， 图 1中 1为坩埚， 2 为石墨护板， 3为氮化硅多孔材料， 4为硅料。
将上述装有硅料的坩埚装入铸锭炉中， 启动铸锭程序， 抽真空， 然后加热， 加热到硅熔点温度， 让其硅料慢慢熔化形成硅熔体。 待硅料全部熔化后开始慢 慢打开隔热笼并降温， 使硅熔体的温度降低形成过冷状态， 形核结晶。 待硅锭定向凝固完。 经退火及冷却工艺， 得到多晶硅锭。
将上述制得的多晶硅锭冷却后， 进行开方得到多晶硅块， 切片后得到多晶 硅片， 采用丝网印刷工艺制作成太阳能电池。
对所得多晶硅锭， 采用光学显微镜（放大 200倍）进行位错观察， 其检测 结果为： 硅锭底部的平均位错密度为 2.57 104 (个 /cm2 ) , 如图 5是硅锭底部 位错检测结果图； 硅锭头部的平均位错密度为 3.31 104 (个 /cm2；), 图 6是硅锭 头部位错检测结果图。
对所得太阳能电池， 采用德国 halm公司电池片检测仪器测定其光电转换效 率。 测定结果为太阳能电池的光电转换效率为 17.4%。
实施例 2
一种多晶硅锭的制备方法， 包括：
采用石英坩埚， 在坩埚内壁喷涂一层氮化硅涂层后。 在坩埚底部铺垫 25块 尺寸为 155 X 155mm的方形碳化硅多孔材料。 铺垫完后， 在碳化硅多孔材料上填 装硅料， 直到全部装完。
将上述装有硅料的坩埚装入铸锭炉中， 启动铸锭程序， 抽真空， 然后加热， 加热到硅熔点温度， 让其硅料慢慢熔化形成硅熔体。 待硅料全部熔化后开始慢 慢打开隔热笼并降温， 使硅熔体的温度降低形成过冷状态， 形核结晶。
待硅锭定向凝固完。 经退火及冷却工艺， 得到多晶硅锭。
将上述制得的多晶硅锭冷却后， 进行开方得到多晶硅块， 切片后得到多晶 硅片， 采用丝网印刷工艺制作成太阳能电池。
对所得多晶硅锭， 采用光学显微镜（放大 200倍）进行位错观察， 其检测 结果为： 硅锭底部的平均位错密度为 2.13 X 104 (个 /cm2 ) ； 硅锭头部的平均位 错密度为 2.99 X 104 (个 /cm2 )。 对所得太阳能电池， 采用德国 halm公司电池片检测仪器测定其光电转换效 率。 测定结果为太阳能电池的光电转换效率为 17.5%。
实施例 3
一种多晶硅锭的制备方法， 包括：
采用石英坩埚， 在坩埚内壁喷涂一层氮化硅涂层后。 在坩埚底部铺垫 25块 尺寸为 155 x l55mm的方形石英多孔材料。 铺垫完后， 在石英多孔材料上填装硅 料， 直到全部装完。
将上述装有硅料的坩埚装入铸锭炉中， 启动铸锭程序， 抽真空， 然后加热， 加热到硅熔点温度， 让其硅料慢慢熔化形成硅熔体。 待硅料全部熔化后开始慢 慢打开隔热笼并降温， 使硅熔体的温度降低形成过冷状态， 形核结晶。
待硅锭定向凝固完。 经退火及冷却工艺， 得到多晶硅锭。
将上述制得的多晶硅锭冷却后， 进行开方得到多晶硅块， 切片后得到多晶 硅片， 采用丝网印刷工艺制作成太阳能电池。
对所得多晶硅锭， 采用光学显微镜（放大 200倍）进行位错观察， 其检测 结果为： 硅锭底部的平均位错密度为 2.03 X 104 (个 /cm2 ) ； 硅锭头部的平均位 错密度为 3.10 X 104 (个 /cm2 )。
对所得太阳能电池， 采用德国 halm公司电池片检测仪器测定其光电转换效 率。 测定结果为太阳能电池的光电转换效率为 17.58%。
实施例 4
一种多晶硅锭的制备方法， 包括：
采用石英坩埚， 在坩埚内壁喷涂一层氮化硅涂层后。 在坩埚底部先铺垫一 层厚度为 lcm的多晶碎料， 再在多晶碎料上铺垫 25块尺寸为 155 x l55mm的方形 氮化硅多孔材料。 铺垫完后， 在氮化硅多孔材料上填装硅料， 直到全部装完。 将上述装有硅料的坩埚装入铸锭炉中， 启动铸锭程序， 抽真空， 然后加热， 加热到硅熔点温度， 让其硅料慢慢熔化形成硅熔体。 待硅料全部熔化后开始慢 慢打开隔热笼并降温， 使硅熔体的温度降低形成过冷状态， 形核结晶。
待硅锭定向凝固完。 经退火及冷却工艺， 得到多晶硅锭。
将上述制得的多晶硅锭冷却后， 进行开方得到多晶硅块， 切片后得到多晶 硅片， 采用丝网印刷工艺制作成太阳能电池。
对所得多晶硅锭， 采用光学显微镜（放大 200倍）进行位错观察， 其检测 结果为： 硅锭底部的平均位错密度为 2.08 X 104 (个 /cm2 ) ； 硅锭头部的平均位 错密度为 2.88 X 104 (个 /cm2 )。
对所得太阳能电池， 采用德国 halm公司电池片检测仪器测定其光电转换效 率。 测定结果为太阳能电池的光电转换效率为 17.62%
实施例 5
多晶硅锭的制备方法， 包括以下步骤：
( 1 )在坩埚底部设置形核源， 形成形核源层；
其中， 在坩埚底部设置形核源为： 采用硅粉与氮化硅粉的混合物共计 300g, 其中硅粉与氮化硅粉按质量比为 6:4, 配合 500ml酒精， 在坩埚底部刷涂上涂层， 在 800度坩埚烘烤箱中烘烤 2小时。 硅粉的粒径为 10um, 氮化硅粉的粒径为 0.5~50
( 2 )在所述形核源层上设置熔融状态的硅料；
其中，在形核源层上设置熔融状态的硅料为： 在形核源层上方装载固体硅料 450~800公斤， 对坩埚进行加热至 1560 °C使得固体硅料熔融， 此时， 熔融状态 的硅料设置于形核源层表面。
图 7为本实施例制备过程的示意图。 其中， 1为坩埚本体， 2为形核源层， 3 为坩埚侧壁上设置的氮化硅层， 4为固体硅料。
( 3 )控制所述坩埚内的温度沿垂直与所述坩埚底部向上的方向逐渐上升形 成温度梯度， 使得所述熔融状态的硅料利用形核源形核结晶， 制得多晶硅锭； 其中， 打开隔热笼， 控制底部温度为 1380°C , 使得硅熔融液达到过冷状态 并利用形核源形核结晶， 得到多晶硅锭。
图 8 为通过光致发光硅片检测系统观测本实施例制得的多晶硅锭的晶界对 位错的阻止作用的照片。 如图 8所示， 在晶界处位错滑移被明显的抑制住， 在 晶界两边形成明显的无位错区和位错区。
本实施例所制得的多晶硅锭位错密度为 1.6 X 10 ~1.8 X 103个 /cm2,少子寿命 为 24微秒（ us ) 。
利用本实施例制得的多晶硅锭制得的多晶硅片适用于制备太阳能电池， 制 得的太阳能电池转换效率为 17.8%。
实施例 6
多晶硅锭的制备方法， 包括以下步骤：
( 1 )在坩埚底部设置形核源， 形成形核源层；
其中， 在坩埚底部设置形核源为： 采用碳化硅与氮化硅粉的混合物共计 200g,其中碳化硅与氮化硅粉按质量比为 8:2,配合 500ml水，利用压缩空气喷枪， 喷涂在坩埚底部， 在 1000度坩埚烘烤箱中烘烤 2小时。 碳化硅和氮化硅粉的粒径 为 20um。
( 2 )在所述形核源层上设置熔融状态的硅料；
其中，在形核源层上设置熔融状态的硅料为： 在形核源层上方装载固体硅料 450~800公斤， 对坩埚进行加热至 1560 °C使得固体硅料熔融， 此时， 熔融状态 的硅料设置于形核源层表面。 ( 3 )控制所述坩埚内的温度沿垂直与所述坩埚底部向上的方向逐渐上升形 成温度梯度， 使得所述熔融状态的硅料利用形核源形核结晶， 制得多晶硅锭； 其中， 打开隔热笼， 控制底部温度为 1300°C , 使得硅熔融液达到过冷状态 并利用形核源形核结晶， 得到多晶硅锭。
本实施例所制得的多晶硅锭位错密度为 7.2 10 ~7.8 X 103个 /cm2,少子寿命 为 20微秒（ us ) 。
利用本实施例制得的多晶硅锭制得的多晶硅片适用于制备太阳能电池，制得 的太阳能电池转换效率为 17. 6%。
实施例 7
多晶硅锭的制备方法， 包括以下步骤：
( 1 )在坩埚底部设置形核源， 形成形核源层；
其中， 在坩埚底部设置形核源为： 采用碳粉和氮化硅粉的混合物共计 300g, 其中碳化硅与氮化硅粉按质量比为 6:4,配合 500ml酒精，在坩埚底部刷涂上涂层， 在 800度坩埚烘烤箱中烘烤 2小时。 碳粉的粒径为 20um, 氮化硅粉的粒径为 5um。
( 2 )在所述形核源层上设置熔融状态的硅料；
其中，在形核源层上设置熔融状态的硅料为： 在另外一个坩埚内加热固体硅 料 450~800公斤， 加热至 1560°C , 制得熔融状态的硅料， 将熔融状态的硅料浇 铸至铺设有形核源层的坩埚内， 此时， 熔融状态的硅料设置于形核源层表面。
( 3 )控制所述坩埚内的温度沿垂直与所述坩埚底部向上的方向逐渐上升形 成温度梯度， 使得所述熔融状态的硅料利用形核源形核结晶， 制得多晶硅锭； 其中， 打开隔热笼， 控制底部温度为 1350°C , 使得硅熔融液达到过冷状态 并利用形核源形核结晶， 得到多晶硅锭。
本实施例所制得的多晶硅锭位错密度为 1.8 X 104~2.0 X 104个 /cm2,少子寿命 为 13微秒（us )
利用本实施例制得的多晶硅锭制得的多晶硅片适用于制备太阳能电池，制得 的太阳能电池转换效率为 17.4%
实施例 8
多晶硅锭的制备方法， 包括以下步骤：
( 1 )在坩埚底部设置形核源， 形成形核源层；
其中， 在坩埚底部设置形核源为： 采用石英粉和氮化硅粉的混合物共计 300g, 其中碳化硅与氮化硅粉按质量比为 6:4, 配合 500ml酒精， 在坩埚底部刷涂 上涂层， 在 800度坩埚烘烤箱中烘烤 2小时。 石英粉的粒径为 lcm, 氮化硅粉的粒 径为 10
( 2 )在所述形核源层上设置熔融状态的硅料；
其中，在形核源层上设置熔融状态的硅料为： 在形核源层上方装载固体硅料 450~800公斤， 对坩埚进行加热至 1560 °C使得固体硅料熔融， 此时， 熔融状态 的硅料设置于形核源层表面。
( 3 )控制所述坩埚内的温度沿垂直与所述坩埚底部向上的方向逐渐上升形 成温度梯度， 使得所述熔融状态的硅料利用形核源形核结晶， 制得多晶硅锭； 其中， 打开隔热笼， 控制底部温度为 1350°C , 使得硅熔融液达到过冷状态 并利用形核源形核结晶， 得到多晶硅锭。
本实施例所制得的多晶硅锭位错密度为 3.0 X 104~3.5 X 104个 /cm2,少子寿命 为 12微秒（ us )
利用本实施例制得的多晶硅锭制得的多晶硅片适用于制备太阳能电池，制得 的太阳能电池转换效率为 17.3%
实施例 9 ( 1 )在坩埚底部设置形核源， 形成形核源层；
其中， 在坩埚底部设置形核源为： 将硅粉与石英硅粉的混合物共计 250g直 接铺设在坩埚底部， 其中硅粉与石英硅粉按质量比为 8: 2。
( 2 )在所述形核源层上设置熔融状态的硅料；
其中，在形核源层上设置熔融状态的硅料为： 在形核源层上方装载固体硅料 450~800公斤， 对坩埚进行加热至 1560 °C使得固体硅料熔融， 此时， 熔融状态 的硅料设置于形核源层表面。
( 3 )控制所述坩埚内的温度沿垂直与所述坩埚底部向上的方向逐渐上升形 成温度梯度， 使得所述熔融状态的硅料利用形核源形核结晶， 制得多晶硅锭； 其中， 打开隔热笼， 控制底部温度为 1360°C , 使得硅熔融液达到过冷状态 并利用形核源形核结晶， 得到多晶硅锭。
本实施例所制得的多晶硅锭位错密度为 3.0 X 10 ~5.0 X 103个 /cm2,少子寿命 为 19微秒（ us ) 。
利用本实施例制得的多晶硅锭制得的多晶硅片适用于制备太阳能电池，制得 的太阳能电池转换效率为 17.7%。
实施例 10
( 1 )在坩埚底部设置形核源， 形成形核源层；
其中， 在坩埚底部设置形核源为： 采用硅粉， 碳化硅粉和氮化硅粉的混合 物共计 250g, 其中硅粉： 碳化硅粉： 氮化硅粉按质量比为 4: 2: 4.配合 400ml酒 精， 在坩埚底部刷涂上涂层， 在 600度坩埚烘烤箱中烘烤 2小时。 硅粉的粒径为 lmm, 碳化娃粉的粒径为 0.5mm, 氮化娃粉的粒径为 0.5~50um。
( 2 )在所述形核源层上设置熔融状态的硅料；
其中，在形核源层上设置熔融状态的硅料为： 在形核源层上方装载固体硅料 450~800公斤， 对坩埚进行加热至 1560 °C使得固体硅料熔融， 此时， 熔融状态 的硅料设置于形核源层表面。
( 3 )控制所述坩埚内的温度沿垂直与所述坩埚底部向上的方向逐渐上升形 成温度梯度， 使得所述熔融状态的硅料利用形核源形核结晶， 制得多晶硅锭； 其中， 打开隔热笼， 控制底部温度为 1360°C , 使得硅熔融液达到过冷状态 并利用形核源形核结晶， 得到多晶硅锭。
本实施例所制得的多晶硅锭位错密度为 5.5 X 104~8.0 X 104个 /cm2,少子寿命 为 11微秒（us ) 。
利用本实施例制得的多晶硅锭制得的多晶硅片适用于制备太阳能电池， 制 得的太阳能电池转换效率为 17.2%。
实施例 11
( 1 )在坩埚底部设置形核源， 形成形核源层；
其中， 在坩埚底部设置形核源为： 采用石英粉 200g直接铺设在坩埚底部原 本涂布设有的氮化硅涂层上。 石英粉的粒径为 0.5~50 μ m。
( 2 )在所述形核源层上设置熔融状态的硅料；
其中，在形核源层上设置熔融状态的硅料为： 在形核源层上方装载固体硅料 450~800公斤， 对坩埚进行加热至 1560 °C使得固体硅料熔融， 此时， 熔融状态 的硅料设置于形核源层表面。
( 3 )控制所述坩埚内的温度沿垂直与所述坩埚底部向上的方向逐渐上升形 成温度梯度， 使得所述熔融状态的硅料利用形核源形核结晶， 制得多晶硅锭； 其中， 打开隔热笼， 控制底部温度为 1360°C , 使得硅熔融液达到过冷状态 并利用形核源形核结晶， 得到多晶硅锭。
本实施例所制得的多晶硅锭位错密度为 4.6 X 103~6.8 X 103个 /cm2,少子寿命 为 20微秒（ us ) 。
利用本实施例制得的多晶硅锭制得的多晶硅片适用于制备太阳能电池， 制 得的太阳能电池转换效率为 17.8%。
效果实施例
为有力支持本发明的有益效果， 特提供对比试验数据如下。
对比试验： 在喷涂好氮化硅涂层的坩埚中装入硅料， 加热到 1560°C熔融， 之后打开隔热笼， 使得底部开始冷却。 长晶完成后进入退火冷却阶段。 完全冷 却后得到多晶硅锭。
本发明实施例 5、 实施例 6和对比试验的对比如下：
表 1. 实施例 5、 实施例 6和对比试验的对比
Figure imgf000020_0001
图 9为带形核层生长出来的多晶硅锭的照片图， 图 10为普通多晶硅锭的照片 图。 从图 9和图 10中可以看出， 带形核层生长出来的多晶硅锭位错少， 晶粒细小 均匀， 生长方向直， 而普通多晶硅锭位错密度高， 晶粒大小不均匀 （一般越亮 表示位错越少， 效率越高。 黑色区域是位错高的区域）。 图 11为本发明实施例 5制得的多晶硅锭头部照片图， 图 12为本发明实施例 5 制得的多晶硅锭尾部照片图， 图 13为本发明对比实施例制得的多晶硅锭头部照 片图， 图 14为本发明对比实施例制得的多晶硅锭尾部照片图。 从图 11~14中可以 看出， 本发明制得的多晶硅锭底部晶粒为 0.5~8毫米， 粒径分布窄 （80%集中在 2~5mm ) , 大小均匀， 规则。 在多晶硅锭中上部晶粒尺寸为 0.5~4厘米， 粒径分 布窄（90%集中在 l~3cm ) ,大小均匀，规则，圆形度高。位错密度低（105个 /cm2 ) , 无明显枝晶和孪晶。
本发明采用设置形核源层制得的多晶硅锭位错密度低于 105个 /cm2, 少子寿 命为 10~25us。 而传统方法得到的硅片位错密度为 105~106 cm2, 少子寿命为 5~10us。 利用所得的多晶硅锭制得的多晶硅片适用于制备太阳能电池， 制得的 太阳能电池转换效率为 17.1~17.8%, 传统的多晶硅片制得的太阳能电池转换效 率为 16.5~17.0%。
实施例 12
多晶硅锭的制备方法， 包括以下步骤：
( 1 )在坩埚底部铺设由熔融法制备得到的无定形石英片，形成微晶形核层； 在微晶形核层上方填装硅料， 直到全部装完； 微晶形核层的厚度为 0.1mm;
( 2 )将上述装有硅料的坩埚装入铸锭炉中， 启动铸锭程序， 抽真空， 然后 加热到 1500 °C , 使硅料全部慢慢熔化。
( 3 ) 当硅料全部熔化后， 即硅熔体熔化的固液界面距坩埚底部高度为 0.1mm 时， 开始慢慢打开隔热笼并降温， 使硅熔体的温度降低， 温度降低幅度 大约为 10k/min, 形成一定的过冷度， 硅熔体开始在无定形石英片基础上开始长 曰 ，
曰曰，
( 4 )待全部硅熔体结晶完后， 经退火冷却得到多晶硅锭。 将上述制得的多晶硅锭冷却后， 进行开方得到多晶硅块， 切片 -清洗后得到 多晶硅片， 以该多晶硅片为原料采用丝网印刷工艺制作成太阳能电池。
对所得多晶硅锭， 采用光学显微镜（放大 200倍）进行位错观察， 其检测 结果为 5.2xl04个 /cm2。
对所得太阳能电池， 采用德国 halm公司电池片检测仪器测定其光电转换效 率。 测定结果为太阳能电池的光电转换效率为 17.5%。
实施例 13
多晶硅锭的制备方法， 包括以下步骤：
( 1 )在坩埚底部铺设微晶玻璃， 形成微晶形核层； 然后在微晶形核层上方 填装硅料， 直到全部装完； 微晶形核层的厚度为 0.5mm;
( 2 )将上述装有硅料的坩埚装入铸锭炉中， 启动铸锭程序， 抽真空， 然后 加热到 1500 °C , 使硅料慢慢熔化。
( 3 )当硅料全部融化后，即硅熔体熔化的固液界面距坩埚底部高度为 0.5mm 时， 开始慢慢打开隔热笼并降温， 使硅熔体的温度降低， 温度降低幅度大约为 15k/min, 形成一定的过冷度， 硅熔体开始在微晶玻璃基础上开始长晶；
( 4 )待全部硅熔体结晶完后， 经退火冷却得到多晶硅锭。
将上述制得的多晶硅锭冷却后， 进行开方得到多晶硅块， 切片 -清洗后得到 多晶硅片， 以该多晶硅片为原料采用丝网印刷工艺制作成太阳能电池。
对所得多晶硅锭， 采用光学显微镜（放大 200倍）进行位错观察， 其检测 结果为 8.2xl04个 /cm2。
对所得太阳能电池， 采用德国 halm公司电池片检测仪器测定其光电转换效 率。 测定结果为太阳能电池的光电转换效率为 17.3%。
实施例 14 多晶硅锭的制备方法， 包括以下步骤：
( 1 )在坩埚底部铺设微晶玻璃和无定形玻璃， 形成微晶形核层； 然后在微 晶形核层上方填装硅料， 直到全部装完； 微晶形核层的厚度为 0.5mm;
( 2 )将上述装有硅料的坩埚装入铸锭炉中， 启动铸锭程序， 抽真空， 然后 加热到 1500 °C , 使硅料慢慢熔化。
( 3 )当硅料全部融化后，即硅熔体熔化的固液界面距坩埚底部高度为 0.5mm 时， 开始慢慢打开隔热笼并降温， 使硅熔体的温度降低， 温度降低幅度大约为 15k/min, 形成一定的过冷度， 硅熔体开始在微晶玻璃和无定形玻璃基础上开始 "^曰曰，
( 4 )待全部硅熔体结晶完后， 经退火冷却得到多晶硅锭。
以上所述是本发明的优选实施方式， 应当指出， 对于本技术领域的普通技 术人员来说， 在不脱离本发明原理的前提下， 还可以做出若干改进和润饰， 这 些改进和润饰也视为本发明的保护范围。

Claims

权 利 要 求
1. 一种多晶硅锭的制备方法， 其特征在于， 包括：
在坩埚底部设置非硅材质形核源层， 在所述非硅材质形核源层上方填装硅 料； 加热使所述硅料熔化， 调节所述坩埚内热场， 使熔化的硅料在所述非硅材 质形核源层基础上开始长晶； 待全部结晶完后， 经退火冷却得到多晶硅锭。
2、 如权利要求 1所述的多晶硅锭的制备方法， 其特征在于， 包括： 在坩埚内壁涂上氮化硅涂层后， 在所述坩埚底部铺垫一层多孔材料形成非 硅材质形核源层， 然后在所述多孔材料上填装硅料；
加热所述填装有硅料的坩埚， 使所述硅料熔化形成硅熔体， 调整热场， 使 硅熔体开始形核结晶；
待硅熔体界面向远离所述坩埚底部的方向移动， 定向结晶凝固完后， 经退 火冷却得到多晶硅锭。
3、 如权利要求 2所述的多晶硅锭的制备方法， 其特征在于， 所述多孔材料 为熔点大于硅的熔点且高温下不与硅发生反应的材质。
4、 如权利要求 2所述的多晶硅锭的制备方法， 其特征在于， 所述多孔材料 为氮化硅、 碳化硅或石英。
5、 如权利要求 2所述的多晶硅锭的制备方法， 其特征在于， 所述多孔材料 的孔径为 0.1cm~5cm。
6、 如权利要求 1所述的多晶硅锭的制备方法， 其特征在于， 包括：
( 1 )在坩埚底部设置形核源， 形成形核源层； 所述形核源选自与硅料的晶 格接近的硅系化合物和 /或与硅料反应生成硅系化合物的材料， 或硅粉、 与硅料 的晶格接近的硅系化合物和与硅料反应生成硅系化合物的材料中的一种或几种 与氮化硅的混合物；
( 2 )在所述形核源层上设置熔融状态的硅料； 所述在形核源层上设置熔融 状态的硅料为： 在所述形核源层上方装载固体硅料， 对所述坩埚进行加热使得 所述硅料熔融， 此时， 所述熔融状态的硅料设置于所述形核源层表面； 或在另 外一个坩埚内加热固体硅料， 制得熔融状态的硅料， 将所述熔融状态的硅料浇 铸至所述铺设有形核源层的坩埚内， 此时， 所述熔融状态的硅料设置于所述形 核源层表面；
( 3 )控制所述坩埚内的温度沿垂直与所述坩埚底部向上的方向逐渐上升形 成温度梯度， 使得所述熔融状态的硅料利用所述形核源形核结晶， 制得多晶硅 键。
7、 如权利要求 6所述的多晶硅锭的制备方法， 其特征在于， 步骤（1 )中所 述设置形核源为将所述形核源涂覆设置在所述坩埚底部， 或者是将所述形核源 直接铺设在所述坩埚底部。
8、 如权利要求 6所述的多晶硅锭的制备方法， 其特征在于， 所述形核源的 粒径为 0.1um~lcm„
9、 如权利要求 6所述的多晶硅锭的制备方法， 其特征在于， 步骤（1 ) 中 所述与硅料的晶格接近的硅系化合物为碳化硅粉或石英粉。
10、 如权利要求 6所述的多晶硅锭的制备方法， 其特征在于， 所述与硅料反 应生成硅系化合物的材料为碳粉。
11、 如权利要求 6所述的多晶硅锭的制备方法， 其特征在于， 步骤（3 ) 中 所述形核结晶过程中控制过冷度为- 1 K~-30K。
12、 如权利要求 1所述的多晶硅锭的制备方法， 其特征在于， 包括
( 1 )在坩埚底部铺设微晶形核层， 所述微晶形核层为微晶硅化物材料和 / 或无定形硅化物材料； 所述微晶形核层的厚度为第一高度值； 所述微晶形核层 为非硅材质形核源层；
( 2 )在所述微晶形核层上方填装硅料， 加热使所述硅料熔化形成硅熔体， 待所述硅料完全熔化后形成的固液界面刚好处在或深入微晶形核层时， 调节热 场形成过冷状态， 使所述硅熔体在微晶形核层基础上开始长晶；
( 3 )待全部硅熔体结晶完后， 经退火冷却得到多晶硅锭。
13、 如权利要求 12所述的多晶硅锭的制备方法， 其特征在于， 待所述硅料 完全熔化， 所述硅化物不熔化时， 即形成的固液界面刚好处在微晶形核层时， 调节热场形成过冷状态， 使所述硅熔体在微晶形核层基础上开始长晶。
14、 如权利要求 12所述的多晶硅锭的制备方法， 其特征在于， 所述微晶硅 化物材料和 /或无定形硅化物材料为熔点高于硅熔点的硅化物。
15、 如权利要求 12所述的多晶硅锭的制备方法， 其特征在于， 所述微晶硅 化物材料为微晶玻璃或微晶陶瓷； 所述无定形硅化物材料为无定形玻璃或熔融 石英。
16、 如权利要求 12所述的多晶硅锭的制备方法， 其特征在于， 所述微晶硅 化物材料和 /或无定形硅化物材料为棒状、 块状、 片状、 条状或颗粒状。
17、 如权利要求 12所述的多晶硅锭的制备方法， 其特征在于， 所述第一高 度值为 l~150mm。
18、 如权利要求 14所述的多晶硅锭的制备方法， 其特征在于， 当所述微晶 形核层为熔点高于硅熔点的微晶硅化物材料和 /或无定形硅化物材料时， 所述第 一高度值为 0.01~30mm。
19、 一种多晶硅锭， 其特征在于， 按照如权利要求 1~18中任一权利要求所 述的制备方法制得。
20、 一种多晶硅片， 其特征在于， 所述多晶硅片为以如权利要求 19所述的 多晶硅锭为原料进行开方 -切片 -清洗后制得。
PCT/CN2013/073361 2012-04-01 2013-03-28 一种多晶硅锭及其制备方法和多晶硅片 WO2013149559A1 (zh)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
CN201210096209.3A CN102776554B (zh) 2012-04-01 2012-04-01 一种多晶硅锭及其制备方法和多晶硅片
CN201210096291.XA CN102776561B (zh) 2012-04-01 2012-04-01 多晶硅锭及其制备方法、多晶硅片和多晶硅铸锭用坩埚
CN201210096209.3 2012-04-01
CN201210096291.X 2012-04-01
CN201310033073.6A CN103074669B (zh) 2013-01-29 2013-01-29 多晶硅锭及其制备方法和多晶硅片
CN201310033073.6 2013-01-29

Publications (1)

Publication Number Publication Date
WO2013149559A1 true WO2013149559A1 (zh) 2013-10-10

Family

ID=49299986

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2013/073361 WO2013149559A1 (zh) 2012-04-01 2013-03-28 一种多晶硅锭及其制备方法和多晶硅片

Country Status (1)

Country Link
WO (1) WO2013149559A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108531983A (zh) * 2018-05-22 2018-09-14 英利能源（中国）有限公司 掺镓多晶硅锭的制备方法及掺镓多晶硅锭

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1546744A (zh) * 2003-12-08 2004-11-17 中国科学院长春光学精密机械与物理研 多晶硅的定向生长方法
CN101597793A (zh) * 2009-07-02 2009-12-09 江西赛维Ldk太阳能高科技有限公司 一种生长多晶硅锭的坩埚
CN101696514A (zh) * 2009-09-30 2010-04-21 常州天合光能有限公司 一种多晶锭的生产方法
CN101768775A (zh) * 2008-12-26 2010-07-07 谭文运 一种定向凝固生长多晶硅锭工艺
CN102776561A (zh) * 2012-04-01 2012-11-14 江西赛维Ldk太阳能高科技有限公司 多晶硅锭及其制备方法、多晶硅片和多晶硅铸锭用坩埚
CN102776554A (zh) * 2012-04-01 2012-11-14 江西赛维Ldk太阳能高科技有限公司 一种多晶硅锭及其制备方法和多晶硅片

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1546744A (zh) * 2003-12-08 2004-11-17 中国科学院长春光学精密机械与物理研 多晶硅的定向生长方法
CN101768775A (zh) * 2008-12-26 2010-07-07 谭文运 一种定向凝固生长多晶硅锭工艺
CN101597793A (zh) * 2009-07-02 2009-12-09 江西赛维Ldk太阳能高科技有限公司 一种生长多晶硅锭的坩埚
CN101696514A (zh) * 2009-09-30 2010-04-21 常州天合光能有限公司 一种多晶锭的生产方法
CN102776561A (zh) * 2012-04-01 2012-11-14 江西赛维Ldk太阳能高科技有限公司 多晶硅锭及其制备方法、多晶硅片和多晶硅铸锭用坩埚
CN102776554A (zh) * 2012-04-01 2012-11-14 江西赛维Ldk太阳能高科技有限公司 一种多晶硅锭及其制备方法和多晶硅片

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108531983A (zh) * 2018-05-22 2018-09-14 英利能源（中国）有限公司 掺镓多晶硅锭的制备方法及掺镓多晶硅锭

Similar Documents

Publication Publication Date Title
WO2013149560A1 (zh) 一种多晶硅锭及其制备方法和多晶硅片
CN102776561B (zh) 多晶硅锭及其制备方法、多晶硅片和多晶硅铸锭用坩埚
CN102268724B (zh) 多晶硅锭及其制造方法、太阳能电池
TWI379020B (en) Methods and apparatuses for manufacturing monocrystalline cast silicon and monocrystaline cast silicon bodies for photovoltaics
JP5380442B2 (ja) 種結晶から鋳造シリコンを製造するための方法および装置
CN102776554B (zh) 一种多晶硅锭及其制备方法和多晶硅片
CN102776555B (zh) 一种多晶硅锭及其制备方法和多晶硅片
TWI620838B (zh) 包含成核促進顆粒之矽晶鑄錠及其製造方法
CN102277618B (zh) 多晶硅锭的制造方法
KR101815620B1 (ko) 폴리결정질 실리콘 잉곳, 이에 의해 제조된 실리콘 웨이퍼 및 폴리결정질 실리콘 잉곳의 제조방법
TWI493082B (zh) 矽晶鑄錠之製造方法
TWI441962B (zh) 矽晶鑄錠及其製造方法（一）
CN102877129B (zh) 一种晶体硅及其制备方法
CN102776560B (zh) 多晶硅锭及其制备方法和多晶硅片
WO2014056157A1 (zh) 多晶硅锭及其制造方法、坩埚
CN103074669B (zh) 多晶硅锭及其制备方法和多晶硅片
CN104203845A (zh) 通过定向凝固制备铸造硅的方法
CN102732943A (zh) 单晶硅铸锭的生产方法
WO2013149559A1 (zh) 一种多晶硅锭及其制备方法和多晶硅片
KR101954785B1 (ko) 다중결정 실리콘 제조방법
EP3494247A1 (en) Crucible for crystallization of molten silicon, process for its manufacture and use thereof
KR101431457B1 (ko) 도가니 보호막 제조 방법
CN112126972A (zh) 籽晶铺设方法、铸锭单晶硅的生产方法和铸锭单晶硅
CN103119207A (zh) 改良半导体材料微结构的技术
JP2007184496A (ja) 結晶半導体粒子の製造方法および光電変換装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13772711

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13772711

Country of ref document: EP

Kind code of ref document: A1