JP2013112570A - Inspection method for refined metal ingot and method for producing high-purity metal containing the same - Google Patents
Inspection method for refined metal ingot and method for producing high-purity metal containing the same Download PDFInfo
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- 229910052751 metal Inorganic materials 0.000 title claims abstract description 130
- 239000002184 metal Substances 0.000 title claims abstract description 128
- 238000000034 method Methods 0.000 title claims abstract description 68
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 23
- 238000007689 inspection Methods 0.000 title claims description 16
- 239000012535 impurity Substances 0.000 claims abstract description 64
- 238000005204 segregation Methods 0.000 claims abstract description 24
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 110
- 229910052710 silicon Inorganic materials 0.000 claims description 110
- 239000010703 silicon Substances 0.000 claims description 110
- 239000013078 crystal Substances 0.000 claims description 41
- 229910021419 crystalline silicon Inorganic materials 0.000 claims description 17
- 239000002994 raw material Substances 0.000 claims description 13
- 238000007711 solidification Methods 0.000 claims description 12
- 230000008023 solidification Effects 0.000 claims description 12
- 230000002093 peripheral effect Effects 0.000 claims description 9
- 239000002210 silicon-based material Substances 0.000 claims description 8
- 238000007670 refining Methods 0.000 claims description 5
- 230000002349 favourable effect Effects 0.000 abstract 1
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 40
- 235000012431 wafers Nutrition 0.000 description 29
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 28
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 26
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 21
- 229910052799 carbon Inorganic materials 0.000 description 15
- 229910052742 iron Inorganic materials 0.000 description 14
- 239000000047 product Substances 0.000 description 13
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 12
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 12
- 239000000463 material Substances 0.000 description 11
- 239000000155 melt Substances 0.000 description 11
- 229910010271 silicon carbide Inorganic materials 0.000 description 11
- 239000007788 liquid Substances 0.000 description 10
- 230000002950 deficient Effects 0.000 description 9
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 8
- 229910052782 aluminium Inorganic materials 0.000 description 8
- 229910052709 silver Inorganic materials 0.000 description 8
- 239000004332 silver Substances 0.000 description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 6
- 238000001816 cooling Methods 0.000 description 6
- 229910002804 graphite Inorganic materials 0.000 description 6
- 239000010439 graphite Substances 0.000 description 6
- 238000004781 supercooling Methods 0.000 description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000002244 precipitate Substances 0.000 description 5
- 238000001556 precipitation Methods 0.000 description 5
- 239000000758 substrate Substances 0.000 description 5
- 230000007547 defect Effects 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 150000002739 metals Chemical class 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 229910052698 phosphorus Inorganic materials 0.000 description 4
- 238000000746 purification Methods 0.000 description 4
- 239000010453 quartz Substances 0.000 description 4
- 239000000377 silicon dioxide Substances 0.000 description 4
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 3
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 239000012300 argon atmosphere Substances 0.000 description 3
- 229910052796 boron Inorganic materials 0.000 description 3
- -1 carbide Chemical class 0.000 description 3
- 238000005266 casting Methods 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000011574 phosphorus Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- DQXBYHZEEUGOBF-UHFFFAOYSA-N but-3-enoic acid;ethene Chemical compound C=C.OC(=O)CC=C DQXBYHZEEUGOBF-UHFFFAOYSA-N 0.000 description 2
- 239000012809 cooling fluid Substances 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 2
- 239000002019 doping agent Substances 0.000 description 2
- 239000005038 ethylene vinyl acetate Substances 0.000 description 2
- 229910052863 mullite Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 239000003566 sealing material Substances 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 2
- 238000004611 spectroscopical analysis Methods 0.000 description 2
- 150000003568 thioethers Chemical class 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- 241001609030 Brosme brosme Species 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- RPPBZEBXAAZZJH-UHFFFAOYSA-N cadmium telluride Chemical compound [Te]=[Cd] RPPBZEBXAAZZJH-UHFFFAOYSA-N 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000009841 combustion method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 230000005496 eutectics Effects 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 1
- 238000013441 quality evaluation Methods 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000005368 silicate glass Substances 0.000 description 1
- 239000011856 silicon-based particle Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
- C01B33/037—Purification
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/20—Metals
- G01N33/205—Metals in liquid state, e.g. molten metals
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
- H01L31/1804—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof comprising only elements of Group IV of the Periodic Table
- H01L31/182—Special manufacturing methods for polycrystalline Si, e.g. Si ribbon, poly Si ingots, thin films of polycrystalline Si
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/546—Polycrystalline silicon PV cells
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/547—Monocrystalline silicon PV cells
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Organic Chemistry (AREA)
- Electromagnetism (AREA)
- Medicinal Chemistry (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Inorganic Chemistry (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Manufacturing & Machinery (AREA)
- Crystallography & Structural Chemistry (AREA)
- Food Science & Technology (AREA)
- Computer Hardware Design (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Silicon Compounds (AREA)
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Photovoltaic Devices (AREA)
Abstract
Description
本発明は、金属精製塊の検査方法、それを含む高純度金属の製造方法およびその用途に関する。 The present invention relates to a method for inspecting a metal refined mass, a method for producing a high-purity metal including the same, and a use thereof.
工業的に様々な種類の元素が様々な用途で必要とされている。酸素や窒素などのガスは単体で自然界に豊富に存在するが、金属元素、特にシリコンなどの半導体材料を含む金属元素は単体で自然界に存在することは非常に稀であり、それらの大部分は酸化物や硫化物などの化合物の混合物として自然界に存在している。したがって、特定の金属元素の単体を得るためには、その酸化物や硫化物の還元および不純物除去などの処理が必要であり、金属元素を安価に高純度化する方法が必要とされている。 Industrially different kinds of elements are needed for different applications. Gases such as oxygen and nitrogen are abundant in nature alone, but metal elements, especially metal elements including semiconductor materials such as silicon, are very rare in nature, and most of them It exists in nature as a mixture of compounds such as oxides and sulfides. Therefore, in order to obtain a single element of a specific metal element, treatments such as reduction of oxides and sulfides and removal of impurities are necessary, and a method for purifying the metal element at low cost is required.
一方、地球環境に様々な問題を引き起こしている石油などの代替として自然エネルギーの利用が注目されている。その中でも太陽電池は大きな設備を必要とせず、稼働時に騒音などを発生しないことから、日本や欧州などで特に積極的に導入されてきている。
カドミウムテルルなどの化合物半導体を用いた太陽電池も一部で実用化されているが、物質自体の安全性やこれまでの実績、またコストパフォーマンスの面から、結晶シリコン基板（ウエハ）を用いた太陽電池（結晶シリコン太陽電池）が大きなシェアを占めている。
On the other hand, the use of natural energy is attracting attention as an alternative to oil and the like that are causing various problems in the global environment. Among them, the solar cell does not require a large facility and does not generate noise during operation, and thus has been particularly actively introduced in Japan and Europe.
Solar cells using compound semiconductors such as cadmium tellurium have also been put into practical use. However, the sun using a crystalline silicon substrate (wafer) from the standpoints of the safety of the material itself, past results, and cost performance Batteries (crystalline silicon solar cells) occupy a large share.
結晶シリコン太陽電池のウエハは、単結晶および多結晶の２つに大別される。
単結晶シリコンウエハは、一般的にＣＺ法およびＦＺ法により製造した単結晶インゴットをスライス加工することにより得られる。一方、多結晶シリコンウエハは、キャスト法（一方向凝固）によりシリコン融液から製造した多結晶インゴット（塊）をスライス加工することにより、リボン法により任意に基板を用いてシリコン融液から直接多結晶シリコンウエハ（リボン）を成長させることにより得られる。
また、ウエハとは形状が異なるが、真空中や不活性ガス中にシリコン液滴を落下させる球状シリコン法により得られたシリコン粒も太陽電池の基材として用いられている。
Crystalline silicon solar cell wafers are broadly divided into two types: single crystal and polycrystal.
A single crystal silicon wafer is generally obtained by slicing a single crystal ingot manufactured by the CZ method and the FZ method. On the other hand, a polycrystalline silicon wafer is obtained by slicing a polycrystalline ingot (lumb) produced from a silicon melt by a casting method (unidirectional solidification), and directly using a substrate by an arbitrary ribbon method. It is obtained by growing a crystalline silicon wafer (ribbon).
Although the shape is different from that of a wafer, silicon particles obtained by a spherical silicon method in which silicon droplets are dropped in a vacuum or an inert gas are also used as a base material for solar cells.
単結晶および多結晶のシリコンウエハ、リボンおよび球状シリコンの製造には、ほとんどの場合、シリコン融液が用いられる。シリコン融液に含まれる金属などの不純物のほとんどは電子デバイス特性に悪影響を与えることから、シリコンの場合にも安価に高純度化する方法が必要とされている。 In most cases, silicon melts are used for the production of monocrystalline and polycrystalline silicon wafers, ribbons and spherical silicon. Since most of impurities such as metals contained in the silicon melt adversely affect the characteristics of electronic devices, a method for purifying the silicon at a low cost is required even in the case of silicon.
高純度シリコン原料の製造方法の１つとして、不純物の凝固偏析などを利用した冶金学的方法がある。この方法は、シーメンス法や流動床法などの気相法と比較して、得られるシリコン中の不純物濃度は少し高いものの、太陽電池特性に影響を与えない程度に、安価に不純物を除去できることから注目されている。以下、シリコンを例に挙げて、不純物除去方法について説明する。 One method for producing a high purity silicon raw material is a metallurgical method utilizing solidification segregation of impurities. Although this method has a slightly higher impurity concentration in the silicon than the gas phase method such as the Siemens method and fluidized bed method, it can remove impurities inexpensively to the extent that it does not affect the solar cell characteristics. Attention has been paid. Hereinafter, the impurity removal method will be described by taking silicon as an example.
シリコン中不純物は次の３種類に分類され、それぞれの物性に合った冶金学的方法により除去される。
（１）ボロンのように偏析係数が大きく、蒸気圧が低い元素
（２）リンのように偏析係数が大きく、蒸気圧が高い元素
（３）金属など偏析係数が極端に小さな元素
Impurities in silicon are classified into the following three types, and are removed by metallurgical methods suitable for each physical property.
(1) Elements with large segregation coefficient such as boron and low vapor pressure (2) Elements such as phosphorus with large segregation coefficient and high vapor pressure (3) Elements such as metals with extremely small segregation coefficient
（１）および（２）の元素は偏析が効き難いため、酸化処理や真空加熱処理などにより不純物を除去する。一方、（３）の元素は基本的には粒界への偏析または固体液体界面の偏析などを利用してその濃度を低減させることができる。
（１）および（２）の元素はウエハの比抵抗調整の観点から制御が重要であるが、（３）の元素は、特に太陽電池の特性面で大きな影響を与えるため、可能な限り低濃度に抑える必要がある。
（３）の元素を除去する方法としては、例えば、内部を冷却流体で冷やした回転冷却体を金属融液に浸漬し、冷却体表面に精製された金属を晶出させる回転偏析法が提案されている（特許第４１１５４３２号公報：特許文献１参照）。
Since the elements (1) and (2) are difficult to segregate, impurities are removed by oxidation treatment or vacuum heat treatment. On the other hand, the concentration of the element (3) can be basically reduced by utilizing segregation at the grain boundaries or segregation at the solid liquid interface.
Control of the elements (1) and (2) is important from the viewpoint of adjusting the specific resistance of the wafer, but the element (3) has a great influence particularly on the characteristics of the solar cell. It is necessary to keep it down.
As a method for removing the element of (3), for example, a rotational segregation method is proposed in which a rotating cooling body whose interior is cooled with a cooling fluid is immersed in a metal melt, and purified metal is crystallized on the surface of the cooling body. (See Japanese Patent No. 4115432: Patent Document 1).
特許文献１の方法では、冷却体に晶出させた金属（以下「精製塊」ともいう）の不純物濃度は、凝固偏析により精製前の溶融金属よりも大幅に低減されることは明らかであり、特に偏析係数の小さい元素での低減効果が顕著である。
しかしながら、実際に得られた精製塊中の不純物濃度を分析評価したところ、特定元素の不純物濃度が、偏析係数から期待される不純物濃度よりも桁違いに高いことがわかった。また、融液中に過飽和により析出した析出物（不純物元素を含む）が凝固偏析というメカニズムではなく、単に析出物として精製塊中に取り込まれる現象も起こることがわかった。
In the method of Patent Document 1, it is clear that the impurity concentration of the metal crystallized on the cooling body (hereinafter also referred to as “refined lump”) is significantly reduced by the solidification segregation than the molten metal before purification. In particular, the reduction effect with an element with a small segregation coefficient is remarkable.
However, when the impurity concentration in the actually obtained refined mass was analyzed and evaluated, it was found that the impurity concentration of the specific element was orders of magnitude higher than the impurity concentration expected from the segregation coefficient. In addition, it was found that the precipitate (including the impurity element) precipitated by supersaturation in the melt does not have a mechanism of solidification segregation but a phenomenon in which the precipitate is simply taken into the purified mass as a precipitate.
このような精製塊を用いて製造された製品、特に太陽電池のような電子デバイスでは、様々な問題が発生する。また、製造途中で精製塊中の不純物を測定して材料を選別することもできるが、測定自体にコストが掛かるために、可能な限り事前に精製塊を検査・選別する、すなわちスクリーニングすることが望ましい。
そこで、本発明は、凝固偏析により金属融液から得られた精製塊中の不純物濃度を簡易にスクリーニングし得る金属精製塊の検査方法、それを含む高純度金属の製造方法およびその用途を提供することを課題とする。
Various problems occur in products manufactured using such purified masses, particularly in electronic devices such as solar cells. In addition, it is possible to measure the impurities in the purified mass during the production process and sort the material. However, since the measurement itself is costly, it is possible to inspect and sort the purified mass in advance as much as possible. desirable.
Therefore, the present invention provides a method for inspecting a purified metal lump that can easily screen the impurity concentration in a purified lump obtained from a metal melt by solidification segregation, a method for producing a high-purity metal including the same, and a use thereof. This is the issue.
本発明者らは、上記の課題を解決すべく様々な検討および考察を重ねた結果、凝固偏析により金属融液から得られた精製塊の表面状態を検査することにより、精製塊のスクリーニングが可能であることを見出し、本発明に至った。 As a result of various studies and considerations to solve the above problems, the present inventors can screen the purified mass by inspecting the surface state of the purified mass obtained from the metal melt by solidification segregation. And found out that the present invention.
かくして、本発明によれば、不純物を含む金属融液に精製塊支持体を接触させ、次いで凝固偏析により前記精製塊支持体の表面に析出させた前記金属融液の金属精製塊に含まれる不純物濃度により規定される前記金属精製塊の良または不良を、前記金属精製塊外周面の表面状態に基づいて検査することを特徴とする金属精製塊の検査方法が提供される。 Thus, according to the present invention, the impurities contained in the metal refined mass of the metal melt brought into contact with the metal melt containing impurities and then deposited on the surface of the refined mass support by solidification segregation. There is provided a method for inspecting a refined metal lump characterized by inspecting the quality of the refined metal lump defined by the concentration based on the surface state of the outer peripheral surface of the refined metal lump.
また、本発明によれば、上記の金属精製塊の検査方法により良とした金属精製塊を高純度金属として得ることを特徴とする高純度金属の製造方法が提供される。 Moreover, according to this invention, the manufacturing method of the high purity metal characterized by obtaining the metal refined lump which was good by the inspection method of said metal refined lump as a high purity metal is provided.
さらに、本発明によれば、上記の高純度金属の製造方法により製造された高純度金属、特に高純度シリコン、前記高純度シリコンを原料として製造された結晶シリコン材料および前記結晶シリコン材料を用いて製造されたシリコン太陽電池が提供される。 Furthermore, according to the present invention, a high-purity metal produced by the above-described method for producing a high-purity metal, particularly high-purity silicon, a crystalline silicon material produced using the high-purity silicon as a raw material, and the crystalline silicon material are used. A manufactured silicon solar cell is provided.
本発明によれば、凝固偏析により金属融液から得られた精製塊中の不純物濃度を簡易にスクリーニングし得る金属精製塊の検査方法、それを含む高純度金属の製造方法およびその用途を提供することができる。
すなわち、本発明によれば、高純度金属、特に高純度シリコンを低価格で市場に供給することが可能となり、結晶シリコン材料なども低価格で供給することが可能となる。さらには、これらを太陽電池用基材として用いることにより、太陽電池を低価格で市場に供給することが可能となる。
According to the present invention, there are provided a method for inspecting a purified metal lump capable of easily screening the impurity concentration in a refined lump obtained from a metal melt by solidification segregation, a method for producing a high-purity metal including the same, and a use thereof. be able to.
That is, according to the present invention, it is possible to supply a high-purity metal, particularly high-purity silicon, to the market at a low price, and it is possible to supply a crystalline silicon material or the like at a low price. Furthermore, it becomes possible to supply a solar cell to a market at low price by using these as a base material for solar cells.
本発明の金属精製塊の検査方法は、金属精製塊外周面の表面の突起数密度を基準突起数密度と比較することで金属精製塊中の不純物含有量の良または不良を検査する場合に、基準突起数密度が３個／ｃｍ2以下である場合に、上記の優れた効果がより発揮される。
また、本発明の金属精製塊の検査方法は、金属精製塊外周面の表面の結晶粒径を基準結晶粒径と比較することで金属精製塊中の不純物含有量の良または不良を検査する場合に、基準結晶粒径が１ｍｍ以上である場合に、上記の優れた効果がより発揮される。
The method for inspecting the metal refined lump of the present invention is to inspect whether the impurity content in the metal refined lump is good or bad by comparing the projection number density on the surface of the metal refined lump outer peripheral surface with the reference protrusion number density. The above excellent effect is more exhibited when the reference protrusion number density is 3 pieces / cm 2 or less.
In addition, the method for inspecting a refined metal lump according to the present invention is for examining whether the impurity content in the refined metal lump is good or bad by comparing the crystal grain size of the surface of the outer periphery of the refined metal lump with the reference crystal grain size. In addition, when the standard crystal grain size is 1 mm or more, the above-described excellent effect is more exhibited.
さらに、本発明の金属精製塊の検査方法は、金属精製塊がシリコン精製塊である場合に、上記の優れた効果がより発揮される。 Furthermore, when the metal refined lump is a silicon refined lump, the above-described excellent effect is more exhibited by the method for inspecting a metal refined lump of the present invention.
（金属精製塊の検査方法）
本発明の金属精製塊の検査方法は、不純物を含む金属融液に精製塊支持体を接触させ、次いで凝固偏析により前記精製塊支持体の表面に析出させた前記金属融液の金属精製塊に含まれる不純物濃度により規定される前記金属精製塊の良または不良を、前記金属精製塊外周面の表面状態に基づいて検査することを特徴とする。
ここで、「金属精製塊外周面」とは、金属精製塊のうち、金属融液からの引き上げ（切り離し）前に金属融液に接触していた部分を意味する。検査においては、その部分の全面であっても、その一部であってもよい。
(Inspection method for metal refining lump)
According to the method for inspecting a refined metal mass of the present invention, a refined mass support is brought into contact with a metal melt containing impurities and then precipitated on the surface of the refined mass support by solidification segregation. The quality of the metal refined lump defined by the concentration of impurities contained is inspected based on the surface state of the outer peripheral surface of the metal refined lump.
Here, the “metal refined lump outer peripheral surface” means a portion of the metal refined lump that has been in contact with the metal melt before being pulled up (separated) from the metal melt. In the inspection, it may be the entire surface or a part thereof.
本発明者らは、表面状態に基づく検査の中でも、特に表面の突起数密度および結晶粒径が最も検査項目として適していることを見出し、かつそのメカニズムの概略を特定した。
以下、一例として黒鉛坩堝中に保持したシリコン融液に精製塊支持体を接触させ、表面に精製塊を析出させた例について説明するが、本発明の金属精製塊の検査方法は、シリコンに限らず、後述する通り、広い金属−不純物系に対して適用可能である。
The inventors have found that the number of protrusions on the surface and the crystal grain size are particularly suitable as inspection items among the inspections based on the surface state, and have specified an outline of the mechanism.
Hereinafter, as an example, an example in which a purified lump support is brought into contact with a silicon melt held in a graphite crucible and the purified lump is deposited on the surface will be described. However, the method for inspecting a purified metal lump according to the present invention is limited to silicon. However, as will be described later, it is applicable to a wide metal-impurity system.
シリコン中の不純物としては、簡単のため２種類とし、金属の一例として鉄と炭素（坩堝起因のものも含む）とする。
シリコンの精製では、精製塊の析出、シリコン原料の再投入、高温でのシリコン原料の融解、低温での保持、精製塊の析出という工程が繰り返される。シリコン精製塊中の鉄濃度は精製前のシリコン融液よりも低濃度であるため、精製工程の繰り返しと共に、シリコン融液中の鉄濃度は徐々に濃化（濃縮）されることになる。
また、シリコン原料中に不純物として炭素を含む場合も同様の現象が起こるが、シリコン原料中に炭素を含まない場合であっても、シリコン融液中の炭素の飽和濃度は高温になるほど高くなることから、高温でのシリコン融解時にシリコン融液中に溶け出した炭素が、低温保持の際に過飽和となり、炭化珪素（ＳｉＣ）粒子として析出するという現象が起こる。
There are two types of impurities in silicon for simplicity, and iron and carbon (including those derived from crucibles) are examples of metals.
In the purification of silicon, the steps of precipitation of purified lump, re-introduction of silicon raw material, melting of silicon raw material at high temperature, holding at low temperature, and precipitation of purified lump are repeated. Since the iron concentration in the silicon refined lump is lower than that in the silicon melt before purification, the iron concentration in the silicon melt is gradually concentrated (concentrated) as the purification process is repeated.
The same phenomenon occurs when carbon is included as an impurity in the silicon raw material, but even when carbon is not included in the silicon raw material, the saturation concentration of carbon in the silicon melt increases as the temperature increases. Therefore, a phenomenon occurs in which carbon dissolved in the silicon melt at the time of melting silicon at a high temperature becomes supersaturated when held at a low temperature and is precipitated as silicon carbide (SiC) particles.
本発明者らの知見によれば、炭化珪素粒子はシリコン融液中に浮遊し、何らかの原因で融液中の流れが変化したときに、シリコン精製塊に取り込まれる。また、シリコン精製塊に取り込まれた炭化珪素粒子は、シリコン精製塊を取り出しの際に、周囲のシリコンを伴って凝固し、突起として現れる。
突起は、金属やそれに含まれる不純物の種類などにより異なるが、例えば金属がシリコンである場合、直径１ｍｍ、高さ０．５ｍｍ程度である。
シリコン結晶中の固溶炭素濃度は数ｐｐｍｗと低く、シリコン精製塊中の炭素濃度は炭化珪素析出物の量でほとんど決まるため、突起数密度を検査することである程度の精度でシリコン精製塊中の炭素濃度を検査することができる。
突起数密度は、シリコン精製塊の表面の目視または顕微鏡観察による計数より検査することができる。
According to the knowledge of the present inventors, silicon carbide particles float in the silicon melt and are taken into the silicon refined mass when the flow in the melt changes for some reason. Further, the silicon carbide particles taken into the silicon refined lump are solidified with surrounding silicon and appear as protrusions when the silicon refined lump is taken out.
The protrusions differ depending on the metal and the type of impurities contained therein. For example, when the metal is silicon, the protrusion has a diameter of about 1 mm and a height of about 0.5 mm.
The solid solution carbon concentration in the silicon crystal is as low as several ppmw, and the carbon concentration in the silicon refined lump is almost determined by the amount of silicon carbide precipitates. The carbon concentration can be inspected.
The projection number density can be inspected by visual or microscopic observation of the surface of the silicon purified mass.
また、予め突起数密度とシリコン精製塊中の炭素濃度との相関を確認しておくことにより、例えば、シリコン精製塊の炭素濃度の規定（仕様）に合せて、特定の突起数密度を基準とすることにより、良または不良を選別することができる。
突起数密度の基準、すなわち基準突起数密度は、金属やそれに含まれる不純物の種類、金属精製塊の仕様などにより異なるが、例えば、太陽電池用のシリコン精製塊では、基準突起数密度を３個／ｃｍ2以下とするのが好ましい。より好ましい基準突起数密度は２個／ｃｍ2以下である。さらにより好ましい基準突起数密度は１個／ｃｍ2以下である。
In addition, by confirming the correlation between the protrusion density and the carbon concentration in the silicon refined lump beforehand, for example, in accordance with the definition (specification) of the carbon concentration of the silicon refined lump, a specific protrusion number density is used as a reference. By doing so, good or bad can be selected.
The standard number of projections, that is, the standard number of projections varies depending on the type of metal and the impurities contained therein, the specification of the refined metal mass, etc. / Cm 2 or less is preferable. A more preferable reference protrusion number density is 2 pieces / cm 2 or less. A more preferable reference protrusion number density is 1 piece / cm 2 or less.
また、本発明者らの知見によれば、不純物が鉄である場合には炭素とは異なる現象が起こる。
シリコン融液中の鉄濃度が高くなると、シリコン精製塊の析出中で部分的に組成的過冷却が発生する。組成的過冷却が起こらない状態では、シリコン精製塊に析出するシリコンは、元の結晶粒の上にエピタキシャル成長するが、シリコン融液内で組成的過冷却が起こると、元の結晶粒の方位を継承せず、多数の結晶核の発生が見られる。したがって、シリコン精製塊の析出時に組成的過冷却が発生したかどうかは、シリコン精製塊の表面の結晶粒径を検査することである程度の精度でシリコン精製塊中の鉄濃度を検査することができる。
結晶粒径は、シリコン精製塊の表面の目視または顕微鏡観察による測定により検査することができる。
Further, according to the knowledge of the present inventors, when the impurity is iron, a phenomenon different from that of carbon occurs.
When the iron concentration in the silicon melt increases, compositional supercooling partially occurs during the precipitation of the silicon refined mass. In a state where compositional supercooling does not occur, the silicon deposited in the silicon refined mass grows epitaxially on the original crystal grains, but when compositional supercooling occurs in the silicon melt, the orientation of the original crystal grains is changed. Many crystal nuclei are observed without inheriting. Therefore, whether or not compositional supercooling has occurred at the time of precipitation of the silicon refined lump can check the iron concentration in the silicon refined lump with a certain degree of accuracy by examining the crystal grain size of the surface of the silicon refined lump. .
The crystal grain size can be inspected by visual or microscopic observation of the surface of the silicon purified lump.
組成的過冷却が発生した場合には、通常の凝固偏析に因らない不純物（ここでは鉄）の取り込みが起こるため、実効偏析係数から期待されるよりも、偏析係数は極端に大きくなる。したがって、シリコン精製塊の鉄濃度の仕様に合せて、特定の結晶粒径を基準とすることにより、良または不良を選別することができる。
結晶粒径の基準、すなわち基準結晶粒径は、金属やそれに含まれる不純物の種類、金属精製塊の仕様などにより異なるが、例えば、太陽電池用のシリコン精製塊では、基準結晶粒径を１ｍｍ以上とするのが好ましい。より好ましい基準結晶粒径は２ｍｍ以上であり、さらに好ましい基準結晶粒径は３ｍｍ以上である。
シリコン精製塊の仕様によっては選別後の良品について、さらにＩＣＰ発光分光分析などの不純物測定が必要となることもあるが、少なくとも極端に不純物濃度の高い精製塊については、事前にスクリーニングが可能であり、不純物分析のコストを省略することができる。
When compositional supercooling occurs, impurities (here, iron) are not taken into account due to normal solidification segregation, so the segregation coefficient becomes extremely larger than expected from the effective segregation coefficient. Therefore, good or bad can be selected by using a specific crystal grain size as a reference in accordance with the specification of the iron concentration of the silicon refined lump.
The standard of crystal grain size, that is, the standard crystal grain size varies depending on the type of metal and impurities contained therein, the specification of the refined metal lump, etc. For example, in the refined silicon mass for solar cells, the standard crystal grain size is 1 mm or more. Is preferable. A more preferable reference crystal grain size is 2 mm or more, and a more preferable reference crystal grain size is 3 mm or more.
Depending on the specifications of the silicon refined mass, it may be necessary to measure impurities, such as ICP emission spectroscopic analysis, for the non-defective product after sorting, but at least the purified mass with extremely high impurity concentration can be screened in advance. The cost of impurity analysis can be omitted.
本発明の金属精製塊の検査方法のうち、精製塊外周面の突起数密度による検査が可能な場合としては、金属と不純物とが炭化物、窒化物、酸化物などの化合物を形成し、その融点が元の金属の融点よりも高く、異物として融液中に浮遊するような場合が考えられ、シリコン以外の金属としては広範囲に渡るが、例えばＡｌやＴｉなどが挙げられ、不純物としては、前記金属中の炭素、窒素、酸素などが挙げられる。
すなわち、上記金属−不純物系においては、前記のシリコンと炭化珪素と同様の状況となり、シリコンと同様にして、本発明の金属精製塊の検査方法を適用することができる。
In the method for inspecting a refined metal lump according to the present invention, the metal and impurities form a compound such as carbide, nitride, oxide, and the like, when the inspection by the number density of protrusions on the outer peripheral surface of the refined lump is possible. Is higher than the melting point of the original metal, and may be floating in the melt as a foreign material, and a wide range of metals other than silicon, such as Al and Ti, the impurities include the above Carbon, nitrogen, oxygen, etc. in a metal are mentioned.
That is, in the metal-impurity system, the situation is similar to that of silicon and silicon carbide, and the method for inspecting a metal refined mass of the present invention can be applied in the same manner as silicon.
また、本発明の金属精製塊の検査方法のうち、精製塊外周面の結晶粒径による検査が可能な系としては、共晶型平衡状態図を示す金属−不純物系であり、かつ不純物増加とともに凝固点降下が起こる系がある。このような金属−不純物系はかなり広範囲に及ぶが、具体例としては例えばＡｌ中のＣａ不純物、Ｃｕ中のＰ、Ｍｇ不純物などが挙げられる。
すなわち、上記金属−不純物系では、前記のシリコン中の鉄不純物と同様に、組成的過冷却による精製塊中への不純物の取り込みと結晶核発生が起こり、結晶粒径が小さくなる。したがって、本発明の金属精製塊の検査方法を適用することができる。
In addition, among the inspection methods of the refined metal lump of the present invention, the system that can be inspected by the crystal grain size of the refined lump outer peripheral surface is a metal-impurity state diagram showing a eutectic equilibrium diagram, and with increased impurities There are systems where freezing point depression occurs. Such a metal-impurity system covers a fairly wide range, and specific examples include Ca impurities in Al, P and Mg impurities in Cu, and the like.
That is, in the metal-impurity system, as in the case of the iron impurities in the silicon, impurities are taken into the refined lump and crystal nuclei are generated by compositional supercooling, and the crystal grain size is reduced. Therefore, the inspection method of the metal refined lump of the present invention can be applied.
本発明の金属精製塊の検査方法を、図面を用いて説明する。
図１は、本発明の金属精製塊の検査方法、（Ａ）精製塊支持体を融液に接触させる前、（Ｂ）精製塊支持体を融液に接触させ、その表面に精製塊が析出している様子および（Ｃ）精製塊を融液から切り離した状態を示す模式図である。
以下の記載以外については、公知の金属精製塊の製造方法（金属の精製方法）に準ずる。
The inspection method of the metal refined lump of this invention is demonstrated using drawing.
FIG. 1 shows a method for inspecting a refined metal lump according to the present invention, (A) before bringing the refined lump support into contact with the melt, (B) bringing the refined lump support into contact with the melt, and depositing the refined lump on the surface. It is a schematic diagram which shows the state which cut | disconnected and the state which separated (C) refined lump from the melt.
Except for the following description, it conforms to a known method for producing a metal refining mass (metal refining method).
図１（Ａ）は、精製塊支持体３を坩堝２中に保持された不純物を含む金属融液１に接触させようとしているところである。
坩堝２の材質は、金属融液１の種類により適宜選択され、黒鉛、シリカ、石英、炭化ケイ素、アルミナ、ムライト、鉄、ステンレス、銅などが挙げられる。例えば、金属がシリコンである場合には、黒鉛、シリカ、石英、炭化ケイ素、アルミナ、ムライトなどが挙げられ、坩堝からの不純物の混入を抑制するためには、黒鉛、シリカ、石英、炭化ケイ素などが好ましい。
精製塊支持体３の材質も坩堝２と同様に金属融液１の種類により適宜選択され、坩堝２に例示の材質が挙げられる。例えば、金属がシリコンである場合には、耐熱性、熱伝導性、不純物混入の観点から黒鉛が好ましい。
FIG. 1A shows that the refined mass support 3 is in contact with the metal melt 1 containing impurities held in the crucible 2.
The material of the crucible 2 is appropriately selected depending on the type of the metal melt 1, and examples thereof include graphite, silica, quartz, silicon carbide, alumina, mullite, iron, stainless steel, and copper. For example, when the metal is silicon, graphite, silica, quartz, silicon carbide, alumina, mullite, and the like can be mentioned. In order to suppress impurities from the crucible, graphite, silica, quartz, silicon carbide, etc. Is preferred.
The material of the refined lump support 3 is also appropriately selected according to the type of the metal melt 1 in the same manner as the crucible 2, and examples of the crucible 2 include materials. For example, when the metal is silicon, graphite is preferable from the viewpoint of heat resistance, thermal conductivity, and impurity mixing.
図１（Ｂ）は、精製塊支持体３を金属融液１に接触させ、その表面に精製塊が析出しているところである。
精製塊支持体３を金属融液１に接触させ、精製塊支持体３を冷却してその温度を低下させることで精製塊支持体３の表面に精製塊４が析出する。
精製塊支持体３を冷却するためには、精製塊支持体３内部に冷却用流体（ガス、液体）を流通させる方法、精製塊支持体３を水冷板などの冷却部品と接触させる方法など公知の方法を用いることができる。
FIG. 1 (B) shows that the purified lump support 3 is brought into contact with the metal melt 1 and the purified lump is deposited on the surface thereof.
The purified mass 4 is deposited on the surface of the purified mass support 3 by bringing the purified mass support 3 into contact with the metal melt 1 and cooling the purified mass support 3 to lower its temperature.
In order to cool the purified lump support 3, a method of circulating a cooling fluid (gas, liquid) inside the purified lump support 3, a method of bringing the purified lump support 3 into contact with a cooling component such as a water cooling plate, and the like are known. This method can be used.
精製塊４を析出させる際には、不純物の偏析により、固液界面の液体側の不純物濃度が高くなり、実効的な偏析係数が大きくなるため、固液界面は常に攪拌し、固液界面の液体側の不純物濃度をできるだけ低く抑えておくことが望ましい。そのためには、例えば、精製塊支持体３の断面形状を円形とし、円を含む平面に垂直で、円の中心を通る線を軸として、前記精製塊支持体３を回転させることが好ましい。 When the purified lump 4 is precipitated, the impurity concentration on the liquid side of the solid-liquid interface increases due to the segregation of impurities, and the effective segregation coefficient increases. Therefore, the solid-liquid interface is always stirred, It is desirable to keep the impurity concentration on the liquid side as low as possible. For this purpose, for example, it is preferable to rotate the refined lump support 3 around a line that passes through the center of the circle perpendicular to the plane including the circle and has a circular cross-sectional shape.
図１（Ｃ）は、精製塊支持体表面に析出した精製塊４の析出後に融液から切り離した状態を示している。
この切り離し後に、金属精製塊外周面の表面状態を上記の方法により検査して、金属精製塊の良否を選別する。
FIG. 1C shows a state where the purified lump 4 deposited on the surface of the purified lump support is separated from the melt after deposition.
After this separation, the surface state of the outer peripheral surface of the metal refined lump is inspected by the above method, and the quality of the metal refined lump is selected.
（高純度金属の製造方法）
本発明の高純度金属の製造方法は、本発明の金属精製塊の検査方法により良とした金属精製塊を高純度金属として得ることを特徴とする。
本発明の金属精製塊の検査方法により不良とされた金属精製塊は、必要に応じて処理に付した後に、再度、金属精製塊の原料として用いればよい。
(Manufacturing method of high purity metal)
The high-purity metal production method of the present invention is characterized in that a refined metal mass is obtained as a high-purity metal by the method for inspecting a metal-purified mass of the present invention.
The metal refined lump made defective by the method for inspecting a metal refined lump of the present invention may be used again as a raw material for the metal refined lump after being subjected to treatment as necessary.
（高純度金属）
本発明の高純度金属（例えば、高純度シリコン）は、本発明の高純度金属の製造方法により製造される。
(High purity metal)
The high-purity metal (for example, high-purity silicon) of the present invention is produced by the method for producing a high-purity metal of the present invention.
（結晶シリコン材料）
本発明の結晶シリコン材料は、本発明の高純度シリコンを原料として製造される。
具体的には、単結晶のシリコンインゴット、多結晶のシリコンインゴットおよびブロック、単結晶および多結晶のシリコンウエハ、シリコンリボンならびに球状シリコンなどが挙げられる。
これらは、公知の方法により製造または加工することにより得られる。
(Crystal silicon material)
The crystalline silicon material of the present invention is produced using the high purity silicon of the present invention as a raw material.
Specific examples include single crystal silicon ingots, polycrystalline silicon ingots and blocks, single crystal and polycrystalline silicon wafers, silicon ribbons, and spherical silicon.
These are obtained by manufacturing or processing by a known method.
例えば、単結晶シリコンインゴットはＣＺ法、多結晶のシリコンインゴットはキャスト法により得られる。
また、多結晶のシリコンブロックは、例えば、バンドソーなどの公知の装置を用いて、多結晶シリコンインゴットにおいて坩堝材料などの不純物が拡散されているおそれのある表面部分を切断加工することにより得ることができる。また、必要に応じて、多結晶シリコンブロックの表面を研磨加工してもよい。
For example, a single crystal silicon ingot can be obtained by the CZ method, and a polycrystalline silicon ingot can be obtained by a casting method.
In addition, a polycrystalline silicon block can be obtained by cutting a surface portion where impurities such as a crucible material may be diffused in a polycrystalline silicon ingot using a known apparatus such as a band saw. it can. Moreover, you may grind | polish the surface of a polycrystalline silicon block as needed.
さらに、単結晶および多結晶のシリコンウエハは、例えば、マルチワイヤーソーなどの公知の装置を用いて、本発明の単結晶シリコンインゴットおよび多結晶シリコンブロックを所望の厚さにスライス加工することにより得ることができる。現状では１７０〜２００μｍ程度が一般的であるが、低コスト化のため徐々に薄型化の傾向にある。 Further, single crystal and polycrystalline silicon wafers are obtained by slicing the single crystal silicon ingot and the polycrystalline silicon block of the present invention to a desired thickness using a known apparatus such as a multi-wire saw. be able to. At present, about 170 to 200 μm is common, but there is a tendency to gradually reduce the thickness for cost reduction.
また、必要に応じて、多結晶シリコンウエハの表面を研磨加工してもよい。
また、シリコンリボンおよび球状シリコンも公知の方法により製造または加工することにより得られる。
Further, if necessary, the surface of the polycrystalline silicon wafer may be polished.
Silicon ribbons and spherical silicon can also be obtained or manufactured by a known method.
（シリコン太陽電池）
本発明のシリコン太陽電池は、本発明の結晶シリコンを用いて製造されてなる。
シリコン太陽電池は、例えば、本発明の結晶シリコン材料を用いて、公知の太陽電池セルプロセスにより製造することができる。例えば、公知の材料を用いて、公知の方法により、ｐ型の不純物がドープされた単結晶および多結晶シリコンウエハの場合、ｎ型の不純物をドープしてｎ型層を形成してｐｎ接合を形成し、表面電極および裏面電極を形成してシリコン太陽電池（太陽電池セル）を得る。
本発明において、「太陽電池」とは、最小ユニットを構成する「太陽電池セル」およびその複数個を電気的に接続した「太陽電池モジュール」を意味し、太陽電池モジュールは、公知の方法により太陽電池セルの複数個を電気的に接続して得ることができる。
(Silicon solar cell)
The silicon solar cell of the present invention is manufactured using the crystalline silicon of the present invention.
A silicon solar cell can be manufactured, for example, by a known solar cell process using the crystalline silicon material of the present invention. For example, in the case of single crystal and polycrystalline silicon wafers doped with p-type impurities by a known method using a known material, an n-type layer is formed by doping an n-type impurity to form a pn junction. Then, a surface electrode and a back electrode are formed to obtain a silicon solar cell (solar cell).
In the present invention, the “solar cell” means a “solar cell” that constitutes a minimum unit and a “solar cell module” in which a plurality of the cells are electrically connected. It can be obtained by electrically connecting a plurality of battery cells.
以下にシリコン精製塊の検査方法および高純度シリコンの製造方法の実施例により本発明を具体的に説明するが、これらの実施例により本発明が限定されるものではない。すなわち、他の金属精製塊の検査方法およびその高純度金属の製造方法である場合にも、金属融液中に析出物として存在している不純物と、金属融液中に溶けている不純物とを、それぞれ炭化珪素および鉄と置き換えることで全く同様に取り扱うことができる。
また、実施例２および３の単結晶シリコンおよび多結晶シリコン以外のシリコンリボン、球状シリコンについてもこれらの実施例と同様に効果が得られる。
Hereinafter, the present invention will be specifically described with reference to examples of a method for inspecting a silicon refined lump and a method for producing high-purity silicon, but the present invention is not limited to these examples. That is, in the case of another method for inspecting a refined metal lump and a method for producing the high-purity metal, impurities present as precipitates in the metal melt and impurities dissolved in the metal melt These can be handled in exactly the same way by replacing them with silicon carbide and iron, respectively.
Further, the effects of the silicon ribbons and spherical silicon other than the single crystal silicon and polycrystalline silicon of Examples 2 and 3 can be obtained in the same manner as in these Examples.
（実施例１）シリコン精製塊の検査
図１の装置内の黒鉛坩堝中に保持した鉄濃度約２０００ｐｐｍｗ、炭素濃度不明のシリコン融液約４００ｋｇに精製塊支持体を接触させ、精製塊支持体の表面にシリコンを析出させて、約１０ｋｇのシリコン精製塊（外径約２８０ｍｍ×長さ約２１０ｍｍ）を連続して１２個製造し、それらを検査した。
具体的には、アルゴン雰囲気にした装置内の坩堝中のシリコン融液を融点＋１８℃に調整し、坩堝上部から精製塊支持体を接触させた。ここでは精製塊支持体を冷却するため、中空の精製塊支持体を用い、内部に低温の窒素ガスを循環させることで、精製塊の析出を促進した。また、精製塊支持体を５０ｒｐｍで回転させ、固液界面を攪拌した状態で精製塊を析出させた。
(Example 1) Inspection of silicon refined lump The refined lump support was brought into contact with about 400 kg of silicon melt having an iron concentration of about 2000 ppmw and an unknown carbon concentration held in the graphite crucible in the apparatus of FIG. Silicon was deposited on the surface, and about 10 kg of silicon refined mass (outer diameter: about 280 mm × length: about 210 mm) was continuously produced, and they were inspected.
Specifically, the silicon melt in the crucible in the apparatus in an argon atmosphere was adjusted to the melting point + 18 ° C., and the purified mass support was brought into contact from the upper part of the crucible. Here, in order to cool the refined lump support, precipitation of the refined lump was promoted by circulating a low-temperature nitrogen gas inside using a hollow refined lump support. Further, the purified lump support was rotated at 50 rpm, and the purified lump was deposited with the solid-liquid interface being stirred.
次いで、得られたシリコン精製塊のシリコン融液から切り離された表面状態を検査した。
具体的には、シリコン精製塊の表面を目視により観察して、直径１ｍｍ×高さ０．５ｍｍ程度以上の大きさの突起を計数してその密度を求め、結晶粒径も測定した。
基準突起数密度を２個／ｃｍ2、すなわち基準値未満のものを良品、基準値以上のものを不良品として評価した。
また、基準結晶粒径を２ｍｍ、すなわち基準値を超えるものを良品、基準値以下のものを不良品として評価した。
検査結果は、シリコン精製塊１２個中、突起数密度が基準値以上である不良品が４個（Ａ）、結晶粒径が基準値以下である不良品が４個（Ｂ）、突起数密度が基準値未満でかつ結晶粒径が基準値を超える良品が４個（Ｃ）であった。
Next, the surface state of the obtained silicon refined lump separated from the silicon melt was inspected.
Specifically, the surface of the silicon refined lump was visually observed, and protrusions having a diameter of about 1 mm × height of about 0.5 mm or more were counted to determine the density, and the crystal grain size was also measured.
The reference projection number density was 2 pieces / cm 2 , that is, a product having a value less than the reference value was evaluated as a non-defective product, and a product having a reference protrusion value or higher was evaluated as a defective product.
Further, the reference crystal grain size was evaluated as 2 mm, that is, a product exceeding the reference value as a non-defective product, and a product having a reference crystal value or less as a defective product.
The inspection results show that among 12 refined silicon ingots, 4 defective products with a projection number density greater than or equal to the reference value (A), 4 defective products with a crystal grain size less than the reference value (B), and the projection number density There were 4 non-defective products having a crystal grain size exceeding the reference value and a crystal grain size exceeding the reference value (C).
各シリコン精製塊から１箇所ずつ分析用のサンプルを採取し、ＩＣＰ発光分光分析により鉄濃度を測定し、燃焼法により炭素濃度を測定し、（Ａ）、（Ｂ）および（Ｃ）の各組の平均値を求めた。
得られた結果を表１に示す。
Samples for analysis are taken from each purified silicon lump, the iron concentration is measured by ICP emission spectroscopic analysis, the carbon concentration is measured by the combustion method, and each set of (A), (B) and (C) The average value of was obtained.
The obtained results are shown in Table 1.
表１の結果から、突起数密度と炭素濃度、結晶粒径と鉄濃度にはそれぞれ相関関係があり、シリコン精製塊の表面状態を検査する本発明の検査方法により、シリコン精製塊の良または不良を選別できることがわかる。 From the results of Table 1, there is a correlation between the number of protrusions and the carbon concentration, the crystal grain size and the iron concentration, and the inspection method of the present invention for inspecting the surface state of the silicon refined ingot shows whether the silicon refined ingot is good or bad. It can be seen that can be selected.
（実施例２）高純度シリコンの製造とそれを用いたデバイス
実施例１で得られた３種類のシリコン精製塊各４０ｋｇを用いて、ＣＺ法により（１００）方位、直径６インチのｐ型単結晶シリコンインゴット（ボディ長３００ｍｍ）の製造を試みた。
具体的には、アルゴン雰囲気にしたＣＺ法装置内の石英坩堝で、ホウ素ドーパント濃度を調整したシリコン精製塊を溶融し、公知の方法により単結晶シリコンの引き上げを実施した。
(Example 2) Production of high-purity silicon and device using the same Using 40 kg of each of the three types of purified silicon ingots obtained in Example 1, (100) orientation, p-type single having a diameter of 6 inches by CZ method An attempt was made to produce a crystalline silicon ingot (body length 300 mm).
Specifically, in a quartz crucible in a CZ method apparatus in an argon atmosphere, a silicon refined lump having an adjusted boron dopant concentration was melted, and single crystal silicon was pulled up by a known method.
しかしながら、突起数密度が基準値以上であるシリコン精製塊（Ａ）では、シリコン融液表面に浮遊している炭化珪素の粒が結晶に付着し、そこから多結晶化が起こり、単結晶シリコンを引き上げることができなかった。
結晶粒径が基準値以下であるシリコン精製塊（Ｂ）および突起数密度が基準値未満でかつ結晶粒径が基準値を超えるシリコン精製塊（Ｃ）については、単結晶シリコンを引き上げることができた。
However, in the silicon refined lump (A) in which the number density of protrusions is equal to or higher than the reference value, silicon carbide particles floating on the surface of the silicon melt adhere to the crystal, and polycrystallization occurs from there. I couldn't raise it.
Single crystal silicon can be pulled up for silicon refined ingots (B) whose crystal grain size is below the reference value and silicon refined ingots (C) in which the number density of protrusions is less than the reference value and the crystal grain size exceeds the reference value. It was.
得られた単結晶シリコンのボディ部から比抵抗が３〜６Ωｃｍ程度の範囲をブロック加工し（１５６ｍｍ×１５６ｍｍ×３００ｍｍ）、次いで１８０μｍ厚にスライスし、ｐ型の単結晶シリコンウエハ約８００枚を得た。得られた単結晶シリコンウエハを以下に示すような通常の太陽電池製造プロセスに投入して、単結晶シリコン太陽電池セルおよび単結晶シリコン太陽電池モジュールを作製した。 From the obtained single crystal silicon body, a block having a specific resistance of about 3 to 6 Ωcm is block processed (156 mm × 156 mm × 300 mm), and then sliced into 180 μm thickness to obtain about 800 p-type single crystal silicon wafers. It was. The obtained single crystal silicon wafer was put into a normal solar cell manufacturing process as shown below to produce a single crystal silicon solar cell and a single crystal silicon solar cell module.
（単結晶シリコン太陽電池セル）
まず、図２に示すように、得られた単結晶シリコンウエハ１１の表面を３％水酸化ナトリウム水溶液でエッチングして、スライスダメージ１ａを除去すると共に、表面にテクスチャ構造を形成した（図３（ａ）参照）。
次に、図３（ｂ）に示すように、単結晶シリコンウエハ１１の表面に、ＰＳＧ（リンシリケートガラス）液４１を塗布し加熱することにより、ＰＳＧ液４１から単結晶シリコンウエハ１１にリンを拡散させ、図３（ｃ）に示すように、単結晶シリコンウエハ１１の受光面側となる表面にｎ+層４２を形成した。このときｎ+層４２上に形成されるＰＳＧ膜４１ａを約１０％のフッ化水素酸により除去した（図３（ｄ）参照）。
(Single crystal silicon solar cells)
First, as shown in FIG. 2, the surface of the obtained single crystal silicon wafer 11 was etched with a 3% aqueous sodium hydroxide solution to remove the slice damage 1a and to form a textured structure on the surface (FIG. 3 ( a)).
Next, as shown in FIG. 3B, a PSG (phosphorus silicate glass) liquid 41 is applied to the surface of the single crystal silicon wafer 11 and heated, so that phosphorus is transferred from the PSG liquid 41 to the single crystal silicon wafer 11. As shown in FIG. 3C, an n + layer 42 was formed on the surface of the single crystal silicon wafer 11 on the light receiving surface side. At this time, the PSG film 41a formed on the n + layer 42 was removed with about 10% hydrofluoric acid (see FIG. 3D).
次に、図３（ｅ）に示すように、プラズマＣＶＤにより、単結晶シリコンウエハ１１のｎ+層４２上に反射防止膜４３として窒化シリコン膜を形成した。
次に、図３（ｆ）に示すように、単結晶シリコンウエハ１１の裏面側となる表面（裏面）にアルミニウムペースト４４ａを塗布し焼成することにより、アルミニウムペースト４４ａからアルミニウムを単結晶シリコンウエハ１１の裏面に拡散させて、図３（ｇ）に示すように、単結晶シリコンウエハ１１の裏面にアルミニウム電極４４とｐ+層４５とを同時に形成した。
Next, as shown in FIG. 3E, a silicon nitride film was formed as an antireflection film 43 on the n + layer 42 of the single crystal silicon wafer 11 by plasma CVD.
Next, as shown in FIG. 3 (f), the aluminum paste 44 a is applied to the front surface (back surface) which is the back surface side of the single crystal silicon wafer 11 and baked, whereby aluminum is converted from the aluminum paste 44 a to the single crystal silicon wafer 11. As shown in FIG. 3G, an aluminum electrode 44 and a p + layer 45 were simultaneously formed on the back surface of the single crystal silicon wafer 11.
次に、図３（ｈ）に示すように、反射防止膜４３の表面上に銀ペースト４６ａを塗布すると共に、単結晶シリコンウエハ１１の裏面上に銀ペースト４７ａを塗布し焼成した。これにより、図３（ｉ）に示すように、ｎ+層４２と電気的に接続する表面電極としての銀電極４６が形成されると共に、単結晶シリコンウエハ１１の裏面と電気的に接続する銀電極４７が形成され、単結晶シリコン太陽電池セル４０を得た。
図４は、得られた単結晶シリコン太陽電池セル４０の受光面の模式的な平面図を示す。図番３１はサブグリッドを示す。
Next, as shown in FIG. 3 (h), a silver paste 46 a was applied on the surface of the antireflection film 43, and a silver paste 47 a was applied on the back surface of the single crystal silicon wafer 11 and baked. As a result, as shown in FIG. 3I, a silver electrode 46 is formed as a surface electrode electrically connected to the n + layer 42, and silver electrically connected to the back surface of the single crystal silicon wafer 11 is formed. Electrode 47 was formed, and single crystal silicon solar battery cell 40 was obtained.
FIG. 4 is a schematic plan view of the light receiving surface of the obtained single crystal silicon solar battery cell 40. FIG. 31 shows a subgrid.
（単結晶シリコン太陽電池モジュール）
得られた単結晶シリコン太陽電池セル４０の複数を電気的に直列に接続することにより単結晶シリコン太陽電池モジュールを作製した（図５参照）。
すなわち、隣り合うようにして配置された、一方の単結晶シリコン太陽電池セルの受光面側の表面電極である銀電極４６と、他方の単結晶シリコン太陽電池セルの裏面側の銀電極４７とが、それぞれインターコネクタと言われる導電性部材５１によって電気的に接続することにより、これらの単結晶シリコン太陽電池セルを電気的に直列に接続して太陽電池ストリングを構成した。
(Single crystal silicon solar cell module)
A plurality of single crystal silicon solar cells 40 obtained were electrically connected in series to produce a single crystal silicon solar cell module (see FIG. 5).
That is, a silver electrode 46 that is a surface electrode on the light receiving surface side of one single crystal silicon solar battery cell and a silver electrode 47 on the back surface side of the other single crystal silicon solar battery cell that are arranged adjacent to each other. These single crystal silicon solar cells were electrically connected in series by electrically connecting them with conductive members 51 called interconnectors to form a solar cell string.
そして、上記の太陽電池ストリングを、透明基板５２としてのガラス基板と、保護シート５３としてのＰＥＴ（ポリエチレンテレフタレート）フィルムとの間に設置された、封止材５４としてのＥＶＡ（エチレンビニルアセテート）透明樹脂中に封止して単結晶シリコン太陽電池モジュールを得た。 Then, the above-described solar cell string is placed between a glass substrate as a transparent substrate 52 and a PET (polyethylene terephthalate) film as a protective sheet 53, and EVA (ethylene vinyl acetate) as a sealing material 54 is transparent. A single crystal silicon solar cell module was obtained by sealing in a resin.
（太陽電池および太陽電池モジュールの特性測定）
得られた太陽電池および太陽電池モジュールの特性をソーラーシミュレータ下で測定した。突起数密度が基準値未満でかつ結晶粒径が基準値を超えるシリコン精製塊（Ｃ）を原料とした単結晶の特性を１００として比較した。
得られた結果を表２に示す。
(Characteristic measurement of solar cells and solar cell modules)
The characteristics of the obtained solar cell and solar cell module were measured under a solar simulator. The characteristics of single crystals made from a silicon refined lump (C) having a protrusion number density less than the reference value and a crystal grain size exceeding the reference value were compared as 100.
The obtained results are shown in Table 2.
表２の結果から、本発明の検査方法により選別されたシリコン精製塊（Ｃ）を原料とした単結晶から製造された太陽電池および太陽電池モジュールが優れた電池特性を有することがわかる。
したがって、本発明により、単結晶シリコン太陽電池および単結晶シリコン太陽電池モジュールのコストパフォーマンスを向上できることがわかる。
From the results in Table 2, it can be seen that solar cells and solar cell modules manufactured from single crystals made from the silicon refined mass (C) selected by the inspection method of the present invention have excellent battery characteristics.
Therefore, it turns out that the cost performance of a single crystal silicon solar cell and a single crystal silicon solar cell module can be improved by this invention.
（実施例３）高純度シリコンの製造とそれを用いたデバイス
実施例１と同条件でシリコン精製塊各２５０ｋｇを製造した。得られたシリコン精製塊について突起数密度および結晶粒径で表面状態を検査したところ、実施例１と同様に（Ａ）、（Ｂ）および（Ｃ）に分類された。
これらの３種類のシリコン精製塊各２５０ｋｇを用いて、キャスト法により坩堝底から一方向凝固させてｐ型多結晶シリコンインゴットを製造して、実施例２と同様にして多結晶シリコン太陽電池セルおよび多結晶シリコン太陽電池モジュールを作製し、それらを検査した。
(Example 3) Production of high-purity silicon and device using the same 250 kg of each silicon refined lump was produced under the same conditions as in Example 1. When the surface state of the obtained silicon refined mass was examined with the number density of protrusions and the crystal grain size, it was classified into (A), (B) and (C) as in Example 1.
Using 250 kg of each of these three kinds of silicon refined ingots, a p-type polycrystalline silicon ingot was produced by unidirectional solidification from the bottom of the crucible by a casting method, and the polycrystalline silicon solar cell and Polycrystalline silicon solar cell modules were fabricated and inspected.
具体的には、アルゴン雰囲気にした装置内に設置した窒化ケイ素の離型剤を塗布したシリカ坩堝（６８０ｍｍ×６８０ｍｍ×高さ４２０ｍｍ）中で、ホウ素ドーパント濃度を調整したシリコン精製塊を溶融し、公知の方法によりｐ型多結晶シリコンインゴットを作製した。
坩堝から多結晶シリコンインゴットを取り出し、バンドソーを用いて１５６ｍｍ角の角柱１６本を切り出した。各角柱のボトム部およびトップ部は不純物や欠陥などの影響で、太陽電池の特性がよくないため、それぞれ１０ｍｍおよび１５ｍｍを切断して多結晶シリコンブロックを得た。その後、ブロックの品質評価として少数キャリアライフタイム測定などを行った後、マルチワイヤーソーを用いて２００μｍ厚にスライスして多結晶シリコンウエハ約７０００枚を得た。多結晶シリコンウエハの比抵抗は１．３〜１．８Ωｃｍであった。
突起数密度が基準値以上であるシリコン精製塊（Ａ）を原料として作製したインゴットでは、ブロック加工に際して、その側面に多数の炭化珪素異物が確認されたため、その部分を全体の約１５％切除してスライス加工に供した。
Specifically, in a silica crucible (680 mm × 680 mm × height 420 mm) coated with a silicon nitride release agent installed in an apparatus in an argon atmosphere, a silicon refined mass adjusted for boron dopant concentration was melted, A p-type polycrystalline silicon ingot was produced by a known method.
A polycrystalline silicon ingot was taken out from the crucible, and 16 156 mm square prisms were cut out using a band saw. Since the bottom part and the top part of each prism are not good in the characteristics of the solar cell due to the influence of impurities and defects, a polycrystalline silicon block was obtained by cutting 10 mm and 15 mm, respectively. Thereafter, minority carrier lifetime measurement and the like were performed as block quality evaluation, and then sliced to a thickness of 200 μm using a multi-wire saw to obtain about 7000 polycrystalline silicon wafers. The specific resistance of the polycrystalline silicon wafer was 1.3 to 1.8 Ωcm.
In an ingot produced using a silicon refined lump (A) having a projection number density of a reference value or more as a raw material, a large number of silicon carbide foreign bodies were found on the side surface during block processing. And subjected to slice processing.
次いで、実施例２と同様にして多結晶シリコン太陽電池セルおよび多結晶シリコン太陽電池モジュールを作製し、それらを検査した。
太陽電池および太陽電池モジュールの出力については、突起数密度が基準値未満でかつ結晶粒径が基準値を超えるシリコン精製塊（Ｃ）を原料とした多結晶の特性を１００として比較した。
多結晶シリコンウエハに炭化珪素の異物が含まれている場合には、逆方向漏れ電流（Ｉｄ）不良が懸念されるため、Ｉｄ不良率についても集計した。
得られた結果を表３に示す。
Next, a polycrystalline silicon solar battery cell and a polycrystalline silicon solar battery module were produced in the same manner as in Example 2, and they were inspected.
Regarding the output of the solar cell and the solar cell module, the characteristics of polycrystals using silicon refined ingot (C) having a protrusion number density less than the reference value and a crystal grain size exceeding the reference value as a raw material were compared as 100.
When a foreign substance of silicon carbide is contained in the polycrystalline silicon wafer, there is a concern about a reverse leakage current (Id) defect, so the Id defect rate was also counted.
The obtained results are shown in Table 3.
表３の結果から、本発明の検査方法により選別されたシリコン精製塊（Ｃ）を原料とした多結晶から製造された太陽電池および太陽電池モジュールが優れた電池特性を有することがわかる。
したがって、本発明により、多結晶シリコン太陽電池および多結晶シリコン太陽電池モジュールのコストパフォーマンスを向上できることがわかる。
一方、予想通り、突起数密度が基準値以上であるシリコン精製塊（Ａ）を原料とした多結晶から製造された太陽電池および太陽電池モジュールのＩｄ不良率は高く、結晶粒径が基準値以下であるシリコン精製塊（Ｂ）を原料とした多結晶から製造された太陽電池および太陽電池モジュールの出力は低かった。
From the results of Table 3, it can be seen that solar cells and solar cell modules manufactured from polycrystals using the silicon refined mass (C) selected by the inspection method of the present invention as raw materials have excellent battery characteristics.
Therefore, it turns out that the cost performance of a polycrystalline silicon solar cell and a polycrystalline silicon solar cell module can be improved by this invention.
On the other hand, as expected, the Id defect rate of solar cells and solar cell modules manufactured from polycrystals made from silicon refined ingots (A) whose protrusion density is equal to or higher than the standard value is high, and the crystal grain size is below the standard value. The output of the solar cell and the solar cell module manufactured from the polycrystal using the silicon refined mass (B) as a raw material was low.
１ 不純物を含む金属融液
２ 坩堝
３ 精製塊支持体
４ 精製塊
１ａ スライスダメージ
１１ 単結晶シリコンウエハ
３１ サブグリッド
４０ 単結晶シリコン太陽電池セル
４１ ＰＳＧ液
４１ａ ＰＳＧ膜
４２ ｎ+層
４３ 反射防止膜
４４ アルミニウム電極
４４ａ アルミニウムペースト
４５ ｐ+層
４６、４７ 銀電極
４６ａ、４７ａ 銀ペースト
５１ 導電性部材
５２ 透明基板
５３ 保護シート
５４ 封止材
DESCRIPTION OF SYMBOLS 1 Metal melt containing impurities 2 Crucible 3 Purified lump support 4 Purified lump 1a Slice damage 11 Single crystal silicon wafer 31 Subgrid 40 Single crystal silicon solar cell 41 PSG liquid 41a PSG film 42 n + layer 43 Antireflection film 44 Aluminum electrode 44a Aluminum paste 45 p + layer 46, 47 Silver electrode 46a, 47a Silver paste 51 Conductive member 52 Transparent substrate 53 Protective sheet 54 Sealing material
本発明は、金属精製塊の検査方法およびそれを含む高純度金属の製造方法に関する。 The present invention relates to a testing method and a high-purity metal manufacturing how containing them metal refining lump.
Claims (11)
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| PCT/JP2012/069998 WO2013080606A1 (en) | 2011-11-29 | 2012-08-06 | Inspection method for metallic purified lump, manufacturing method for high-purity metal including same, and uses for same |
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| JP2019137566A (en) * | 2018-02-07 | 2019-08-22 | 信越半導体株式会社 | Method for measuring carbon concentration in silicon crystal |
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| JPH0526803A (en) * | 1991-07-23 | 1993-02-02 | Shin Etsu Handotai Co Ltd | Method for analyzing silicon crystal for impurity |
| JPH05232104A (en) * | 1991-03-29 | 1993-09-07 | Mitsubishi Materials Corp | Method for determining impurity concentration in single-crystal silicon rod |
| JP2001021463A (en) * | 1999-07-02 | 2001-01-26 | Komatsu Electronic Metals Co Ltd | Jig and method for sampling |
| JP2001172729A (en) * | 1999-12-13 | 2001-06-26 | Showa Alum Corp | Apparatus and method for refining metal |
| JP2006027940A (en) * | 2004-07-14 | 2006-02-02 | Sharp Corp | Method for refining metal |
| JP2008303113A (en) * | 2007-06-08 | 2008-12-18 | Shin Etsu Chem Co Ltd | Unidirectional coagulation method for silicon |
| WO2009130786A1 (en) * | 2008-04-25 | 2009-10-29 | テイーアンドエス インベストメント リミテッド | Process for producing silicon material for solar cell |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05232104A (en) * | 1991-03-29 | 1993-09-07 | Mitsubishi Materials Corp | Method for determining impurity concentration in single-crystal silicon rod |
| JPH0526803A (en) * | 1991-07-23 | 1993-02-02 | Shin Etsu Handotai Co Ltd | Method for analyzing silicon crystal for impurity |
| JP2001021463A (en) * | 1999-07-02 | 2001-01-26 | Komatsu Electronic Metals Co Ltd | Jig and method for sampling |
| JP2001172729A (en) * | 1999-12-13 | 2001-06-26 | Showa Alum Corp | Apparatus and method for refining metal |
| JP2006027940A (en) * | 2004-07-14 | 2006-02-02 | Sharp Corp | Method for refining metal |
| JP2008303113A (en) * | 2007-06-08 | 2008-12-18 | Shin Etsu Chem Co Ltd | Unidirectional coagulation method for silicon |
| WO2009130786A1 (en) * | 2008-04-25 | 2009-10-29 | テイーアンドエス インベストメント リミテッド | Process for producing silicon material for solar cell |
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| JP2019137566A (en) * | 2018-02-07 | 2019-08-22 | 信越半導体株式会社 | Method for measuring carbon concentration in silicon crystal |
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