准单晶硅铸锭过程中加热功率及硅料堆积孔隙率对籽晶熔化的影响

人工晶体学报 ›› 2022, Vol. 51 ›› Issue (9-10): 1755-1768.

准单晶硅铸锭过程中加热功率及硅料堆积孔隙率对籽晶熔化的影响

孙英龙¹, 郑丽丽¹, 张辉²

1.清华大学航天航空学院,北京 100084;
2.清华大学工程物理系,北京 100084

收稿日期:2022-05-10 出版日期:2022-10-15 发布日期:2022-11-02
通信作者: 郑丽丽,博士,教授。E-mail:zhenglili@tsinghua.edu.cn
作者简介:孙英龙(1988—),男,吉林省人,博士研究生。E-mail:sunyl19@mails.tsinghua.edu.cn。
郑丽丽,清华大学教授,博士生导师,《人工晶体学报》编委。研究领域涵盖燃烧科学、电磁流体、热科学与流体力学及其在航空航天(超音速燃烧)、材料制备过程与技术(热涂层、晶体生长、光伏太阳能材料)中的应用。2000年获得美国国家科学基金会(NSF)给予前沿科学研究青年学者最高荣誉的CAREER奖,2008年被授予教育部“长江学者特聘教授”。发表学术论文约160余篇,其中SCI收录80余篇。
基金资助:
国家重点研发计划(2020YFB1506501)

Effect of Heating Power and Porosity of Stacked Silicon on Seed Crystal Melting during Quasi-Single Crystalline Silicon Casting Process

SUN Yinglong¹, ZHENG Lili¹, ZHANG Hui²

1. School of Aerospace Engineering, Tsinghua University, Beijing 100084, China;
2. Department of Engineering Physics, Tsinghua University, Beijing 100084, China

Received:2022-05-10 Online:2022-10-15 Published:2022-11-02

摘要/Abstract

摘要： 本文在考虑硅料的堆积孔隙率和熔化变形等因素的基础上,建立了基于多孔介质的堆积硅料简化模型,对光伏太阳能用准单晶硅铸锭系统的硅料熔化过程进行了数值模拟,研究了不同侧/顶加热器功率比、堆积孔隙率以及加热器总功率对籽晶熔化的影响。研究结果表明:硅料的熔化时间和籽晶的熔化比例取决于侧/顶加热器功率比,降低侧/顶加热器功率比和堆积孔隙率有助于籽晶的有效保留,但会导致籽晶的熔化界面形状发生变化,使杂质在籽晶熔化界面形状为“凹”的区域内聚集,进而影响后续晶体生长的质量;当加热器的总功率低于临界值之后,籽晶的熔化界面形状会在靠近坩埚壁面的边缘区域发生变化,导致不均匀成核的发生,不利于准单晶硅铸锭的生产。在实际工况条件下,可以根据由侧/顶加热器功率比、堆积孔隙率、加热器总功率、籽晶的熔化比例和状态绘制的等值线图对工艺参数进行合理配置。

关键词: 准单晶硅铸锭, 加热功率, 堆积孔隙率, 籽晶熔化, 界面形状, 熔化状态

Abstract: Based on the porous media model, a simplified model of stacked silicon was established to consider stacked porosity and melting deformation. This model was applied to numerical simulate the stacked silicon melting process of the quasi-single crystalline silicon casting system for photovoltaic solar application. Effects of the power ratios of side/top heaters, stacked porosity, and total power of heaters on the seed crystal melting process were studied. The results show that the melting time of silicon and the melting ratio of seed crystal depend on the power ratio of side/top heaters. Reducing the power ratio and the porosity is beneficial to the retention of seed crystal, nevertheless, it changes the interface shape after seed crystal melting. The impurities can gather in the concave region of the interface after seed crystal melting. Such distribution of impurities affects the quality of subsequent grown crystals. When the total power of the heater is below the critical value, the interface shape after seed crystal melting also changes near the edge of the crucible wall. This change can lead to uneven nucleation, which is not desirable for the production of quasi-single crystalline silicon. Therefore, the process parameters under the actual working conditions shall be configured according to the contour map, which is determined by the power ratio of side/top heaters, stacked porosity, the total power of heaters, the melting ratio of the seed crystal, and the melting state of the seed crystal.

Key words: quasi-single crystalline silicon casting, heating power, stacked porosity, seed crystal melting, interface shape, melting state

中图分类号:

O782
TQ127.2

孙英龙, 郑丽丽, 张辉. 准单晶硅铸锭过程中加热功率及硅料堆积孔隙率对籽晶熔化的影响[J]. 人工晶体学报, 2022, 51(9-10): 1755-1768.

SUN Yinglong, ZHENG Lili, ZHANG Hui. Effect of Heating Power and Porosity of Stacked Silicon on Seed Crystal Melting during Quasi-Single Crystalline Silicon Casting Process[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2022, 51(9-10): 1755-1768.

参考文献

[1] MA X, ZHENG L L, ZHANG H, et al. Thermal system design and optimization of an industrial silicon directional solidification system[J]. Journal of Crystal Growth, 2011, 318(1): 288-292.
[2] GAO B, NAKANO S, HARADA H, et al. Reduction of polycrystalline grains region near the crucible wall during seeded growth of monocrystalline silicon in a unidirectional solidification furnace[J]. Journal of Crystal Growth, 2012, 352(1): 47-52.
[3] MA W C, ZHONG G X, SUN L, et al. Influence of an insulation partition on a seeded directional solidification process for quasi-single crystalline silicon ingot for high-efficiency solar cells[J]. Solar Energy Materials and Solar Cells, 2012, 100: 231-238.
[4] YU Q H, LIU L J, MA W C, et al. Local design of the hot-zone in an industrial seeded directional solidification furnace for quasi-single crystalline silicon ingots[J]. Journal of Crystal Growth, 2012, 358: 5-11.
[5] BLACK A, MEDINA J, PIÑEIRO A, et al. Optimizing seeded casting of mono-like silicon crystals through numerical simulation[J]. Journal of Crystal Growth, 2012, 353(1): 12-16.
[6] MA X, ZHENG L L, ZHANG H. System design and hot zone optimization of monocrystalline silicon directional solidification furnace for PV application[J]. Journal of Crystal Growth, 2014, 385: 28-33.
[7] LI Z Y, LIU L J, ZHANG Y F, et al. Preservation of seed crystals in feedstock melting for cast quasi-single crystalline silicon ingots[J]. International Journal of Photoenergy, 2013, 2013: 670315.
[8] 李早阳,刘立军,余庆华.准单晶硅铸锭过程中种晶的保存及其界面的控制[C].上海: 第八届中国太阳级硅及光伏发电研讨会, 2012.
LI Z Y, LIU L J, YU Q H, Preservation of seed crystal and control of seed-melt interface during quasi-single crystalline silicon casting process[C].Shanghai: 8th China SoG Silicon and PV Power Conference, 2012.
[9] 贾存龙.独立控制隔热环对籽晶保护作用分析[J].河南科技,2014(17):74-75.
JIA C L. Analysis of independent control of insulation ring for seed crystal protection[J]. Journal of Henan Science and Technology, 2014(17): 74-75(in Chinese).
[10] 余庆华,刘立军,钟根香,等.准单晶硅铸锭过程中凝固界面形状的控制[J].工程热物理学报,2013,34(3):505-508.
YU Q H, LIU L J, ZHONG G X, et al. Control of solidification front shape during quasi-single crystalline silicon casting process[J]. Journal of Engineering Thermophysics, 2013, 34(3): 505-508(in Chinese).
[11] 张运锋,孟庆超,刘磊,等.多晶硅铸锭过程中的籽晶熔化控制[J].电子技术与软件工程,2017(15):115.
ZHANG Y F, MENG Q C, LIU L, et al. Control of the melting of seed crystal during polysilicon casting process[J]. Electronic Technology & Software Engineering, 2017(15): 115(in Chinese).
[12] 孟庆超,张运锋,刘磊,等.准单晶硅铸锭过程中固液相变界面形状的控制[J].太阳能学报,2015,36(7):1545-1549.
MENG Q C, ZHANG Y F, LIU L, et al. Melt-solid interface shape control in the casting process for quasi-single crystalline silicon ingots[J]. Acta Energiae Solaris Sinica, 2015, 36(7): 1545-1549(in Chinese).
[13] MA Q L, ZHENG L L, ZHANG G J, et al. Numerical modeling of sintering and dehydroxylation of porous silica preform for low-hydroxyl silica glass fabrication[J]. Ceramics International, 2020, 46(14): 23067-23083.
[14] 谢广杰.多晶硅真空定向凝固过程传热特性及其对铸锭质量的影响研究[D].昆明:昆明理工大学,2018.
XIE G J. Study on heat transfer characteristics of polycrystalline silicon during vacuum directional solidification and its influence on ingot quality[D]. Kunming: Kunming University of Science and Technology, 2018(in Chinese).
[15] 周力,王新华,邓小旋,等.关于连铸传热数学模型中等效导热系数的讨论[J].连铸,2015,40(4):18-23.
ZHOU L, WANG X H, DENG X X, et al. Discussion of effective thermal conductivity in heat transfer models of continuous casting[J]. Continuous Casting, 2015, 40(4): 18-23(in Chinese).