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Czochralski single crystalline silicon@ growth - gives improved yield of defect-free bars due to optimisation of particle distribution, roughness, fracture and pull strength of the polycrystalline grains continuously added
Czochralski single crystalline silicon@ growth - gives improved yield of defect-free bars due to optimisation of particle distribution, roughness, fracture and pull strength of the polycrystalline grains continuously added
Si single crystals are grown using a Czochralski method with continuous resupply of granular polycrystalline Si. Granular material properties are optimised as follows: average surface roughness is not more than 0.5 micron, obtd. by cleaning of the granules, pref. using a watery HF soln., the number of granules with a dia. of 2 mm or more is not more than 1000 per 1 kg of material; the average ratio of cavity area to grain area is not more than 3%; the fracture strength KIC is not less than 1.5; the pull strength is not less than 15 kg/mm2; the polysilicon is pref. made by thermal decompsn. of silane or trichlorosilane in a fluid bed reactor. USE/ADVANTAGE - The optimisation of the granular material reduces the number of fracture pieces formed and thereby increases the yield of single crystalline bars without defects. Analysis has shown that fracture occurs due to the thermal shock and that the number of pieces formed depends on size and strength of the grains and number of potential fracture sites. The method is used in the growth of Si crystals, esp. for large, e.g. larger than 6 inch dia., bars.
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机译:使用切克劳斯基(Czochralski)方法生长Si单晶,并连续补充颗粒状多晶Si。粒状材料的性能优化如下:平均表面粗糙度不超过0.5微米(obtd)。通过清洗颗粒,优选。使用含水HF溶液,用直径的颗粒数。每1千克材料2毫米或更大的数量不超过1000;型腔面积与晶粒面积的平均比值不大于3%;断裂强度KIC不小于1.5。抗拉强度不小于15 kg / mm2;多晶硅是优选的。由热解压缩制成。在流化床反应器中加入硅烷或三氯硅烷。使用/优势-粒状材料的优化减少了断裂片的数量,从而提高了无缺陷单晶棒的产量。分析表明,由于热冲击而发生断裂,形成的碎片数量取决于晶粒的尺寸和强度以及潜在的断裂部位的数量。该方法主要用于硅晶体的生长。对于大型直径大于6英寸的钢筋。
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