简述多晶硅技术的发展趋势

近年来,由于低成本、低耗能和少污染的优势,铸造多晶硅成为主要的光伏材料之一,越来越受到人们的广泛关注。本文阐述了当前国内外多晶硅铸造过程中的一些核心技术,如坩埚免喷涂、坩埚免烧结、单炉产量提高、准单晶铸造、多晶硅铸造生长大晶粒及氮化硅粉回收等,并简单介绍了坩埚免烧结技术的实际运用情况。     

Investigation on Slicing Behavior of Single Crystal Silicon Wafer in AWJM and Influence of Micro Dimple Textured Surface for Solar Applications

Silicon - The current investigation focuses on the slicing characteristics of silicon, a hard and brittle solid that is very difficult to cut, with abrasive water jet machining (AWJM) process by...     

Experimental Investigation for Generation of Micro-Holes on Silicon Wafer Using Electrochemical Discharge Machining Process

Silicon - Electrochemical discharge machining (ECDM) is a versatile machining process due to its applicability to machine different materials regardless to their properties. In this work, machining...     

Numerical Study on Effect of Side Insulation Movement in the Multi-crystalline Silicon Growth Process

Silicon - Numerical simulation is the best tool to understand and optimize the directional solidification (DS) process to grow good quality multi crystalline silicon (mc-Si) ingot for PV...     

Computational Modelling on Heat Transfer Study of Molten Silicon During Multi-crystalline Silicon Growth Process for PV Applications

Multi-crystalline silicon is an important material with advantages of low-production cost and high conversion efficiency for photovoltaic solar cells. Directional solidifi cation has become the main technique for producing mc-Si ingots for solar cell applications. The study is performed in the framework of the incompressible Navier-Stokes equation in the Boussinesq approximation with convection-conduction equations. The computations are carried out in a two dimensional (2D) axisymmetric model by the finite- element method. The influence of the Reynolds numbers, total heat flux and velocity streamline pattern on the silicon melt was simulated and analyzed for various Rayleigh numbers between 10 to 10 ⁶ with the help of a numerical technique. The following key findings are presented in this paper. The velocity field value is increased above 0.02(m/s), heat flux value is increased to 10 ⁴(W/m ²), when the Rayleigh number is increased above 1000. Reynolds numbers are also studied in five parallel horizontal cross-sections of the melt silicon region for various Prandtl numbers at a critical Rayleigh number of 1000. Reynolds numbers are varied between 100 and 10 ⁵ for the Rayleigh numbers between 10 to 10 ⁶. Meanwhile, the melt has high fluctuation when the Prandtl number is increased above 0.01. The flow is converted from laminar to turbulence at a critical Rayleigh number 1000 and Prandtl number 0.01. These results provide important information for controlling the melt fluctuations during the solidification process which are used to increase the average grain size in growing silicon multicrystals and reduce the dislocation density.     

Assessment and Study on the Impact on Environment by Multi-crystalline Silicon Preparation by Metallurgical Route

Silicon - The process of the production of multi-crystalline silicon is also that of incessant purification of metallurgical grade silicon, during which high energy consumption and environmental...     

Actiflo(R)工艺技术应用于硅片研磨废水处理

考虑到硅片研磨废水浊度高、悬浮固体粒径小及难于沉淀的水质特点,并依据处理水量的增加和后期回用的要求,采用Actiflo(R)砂压载絮凝工艺对现有的混凝沉淀处理装置进行升级改造.改造后处理能力由原来不到20 m3/h提高到40 m3/h,表明Actiflo(R)砂压载絮凝工艺对难处理的高浊度硅片研磨废水具有稳定且良好的处理效果.进水浊度平均值为2 120 NTU,装置处理后出水浊度小于10 NTU,浊度去除率高达99％以上.     

高效硅片切割液TF-033的研究

通过分子构效关系的研究及合理的配方设计,以低泡嵌段聚醚和梳型结构分散剂为主要原料,添加润湿剂、抗氧化剂、防腐剂、消泡剂等表面活性剂,研制了一种硅片切割液TF-033。它具有低粘度、高分散性、高润滑性等特点。一方面能有效解决因砂浆沉积引起的脏污片问题,提高切片稳定性和成品率,另一方面大幅降低了设备能耗,进而达到降本增效的目的。     

Effect of Silicon Wafer Resistivity on Morphology and Wettability of Silicon Nanowires Arrays

Silicon - Herein, we prepare vertical and single crystalline silicon nanowires (SiNWs) via a one-step metal-assisted chemical etching method in aqueous NH4HF2/AgNO3 solution. The effects of silicon...     

Improving Heat Transfer Properties of DS furnace by the Geometrical Modifications for Enhancing the Multi Crystalline Silicon Ingot (mc-Si) Quality Using Transient Simulation

Silicon - Heat transfer plays a main role on Directional Solidification (DS) process that determines the multi-crystalline silicon (mc-Si) ingot quality. The 2D axi-symmetric model based numerical...     

化学机械研磨浆料对硅片质量的影响

在化学机械研磨过程中,对半导体硅片的质量影响因素主要有研磨工艺(研磨盘压力、转速、浆料流量等)和化学机械研磨液的成分。本论文重点研究了化学机械研磨浆料的成分对硅片表面粗糙度、总厚度偏差(TTV)、拉丝、划道擦伤、清洁度的影响。通过实验可知:研磨浆料组成为:1%AEO_7;2%聚乙烯吡咯烷酮PVP K90;0.4%乙二胺四乙酸;2%四羟乙基乙二胺;20%PWA 10;74.6%高纯水,可以得到优异的研磨硅片质量。     

Investigation of DS Furnace Heat Exchange Block Thickness for the Improvement mc-Si Ingot Quality

Silicon - Numerical investigation was performed for analyzing the distribution of von Mises stress in the growing multi-crystalline silicon ingot during the directional solidification process. In...     

不同摩擦偶件对单晶硅摩擦磨损行为影响的对比研究

对比研究A12O3和玛瑙球对单晶硅摩擦磨损行为的影响.结果表明:单晶硅与Al2O3和玛瑙球对摩时.摩擦因数均随滑动速度的增加而降低,二者与单晶硅对摩时的摩擦因数相差很小:与Al2O3和玛瑙球对摩时,单晶硅的磨损体积损失均随滑动速度的增加而减小;在相同实验条件下,与Al2O3球对摩时;单晶硅的磨损体积损失明显大于与玛瑙球...     

利用双液浮选法回收硅片切割废料中SiC的试验研究

研究了以煤油作为捕收剂和载体回收硅片切割废料中碳化硅的双液浮选工艺.研究捕收剂用量、pH值、固液比及粒度对回收碳化硅纯度的影响.通过单因素及正交试验,综合考虑极差分析和方差分析的结果,确定最优工艺条件为:捕收剂用量50mL·g-1、pH值为8.3、固液比为3∶400g·mL-1、粒度8.636μm,此条件下回收的碳化硅纯度达到99.08％.采用双液浮选工艺回收太阳能硅片切割废料中的碳化硅粉体具有显著的经济效益和社会效益.     

Crystal Structure of Silicon Powders Produced from Laser-Heated Silane

The crystallinity and microstructure of fine silicon particles produced by the decomposition of laser-heated silane gas were studied in as-synthesized and annealed states. Amorphous, partially crystalline, and fully crystalline particles can be produced. With annealing at 550°C, partially crystalline particles become fully crystalline; amorphous particles remain amorphous. The results agree with previous interpretations of formation, growth, and crystallization processes in the reaction zone based on light scattering and transmission diagnostics.     

利用太阳能多晶硅片生产过程中产生的固体废弃物合成莫来石晶须

以太阳能多晶硅片生产过程中产生的废弃石英坩埚及废弃超细氧化铝磨料为原料,以硫酸钠、硫酸钾复合盐作为熔盐体系制备莫来石晶须.同时,采用XRD,SEM等测试手段研究了不同温度下所合成粉体的物相及形貌分析.结果表明,在1100℃高火保温3h制备出了直径为0.1～2μm,长径比高达50～60的莫来石晶须,其形成机理属于熔解-沉淀反应机制.     

Mechanochemical Polishing of Silicon Carbide Single Crystal with Chromium(III) Oxide Abrasive

In order to clarify the mechanism of mechanochemical polishing of SiC with Cr₂O₃ abrasive, 6H-wurtzite single-crystal specimens were dry-polished. A significant anisotropic polishing rate difference was found between Si(0001) and C(000 1 ) surfaces. The C(000 1 ) surface was removed 10 times as fast. Polished surfaces were observed from cross-sectional and plan-view directions by high-voltage TEM. There was no trace of mechanical effects such as residual strain or scratches. The polishing debris was analyzed by X-ray diffraction, high-resolution TEM, and analytical TEM. No crystalline phases were identified from X-ray diffraction patterns except for Cr₂O₃, while it was found from TEM observation that a large amount of an amorphous phase consisting of Si, C, and O was contained in the debris. These results indicated that the surface of SiC was removed mechanochemically by the aid of a catalytic oxidation effect of Cr₂O₃.     

石英坩埚内高纯隔离层在高效多晶硅铸锭中的应用

多晶硅铸锭过程中,石英坩埚侧壁中的杂质通过固相扩散进入并残留在多晶硅锭的边部,形成多晶硅锭边部的低少子寿命区(边部红区).本文通过在坩埚侧壁上制作三种不同成分的高纯隔离层来阻挡坩埚侧壁中的杂质向硅锭中的扩散,以降低硅锭中的边部红区比例.结果表明采用掺钡高纯隔离层可以使硅锭中的边部红区显著变窄,基本消除硅方中的边部红区.     

铅晶质玻璃在不同环境下的铅析出性能研究

铅水晶玻璃具有折射率高、透过率高等优异性能,被广泛应用于工艺品、高档餐具、首饰等,但其中氧化铅成分存在潜在析出的风险,因此对使用者的健康有一定的影响。通过制备3种不同Pb_3O_4质量分数的铅水晶玻璃样品,分别研究了80℃条件下样品在白酒、洗洁精中浸泡后的铅析出情况,并通过失重法、光学显微镜以及元素分析(ICP)测试,对铅水晶玻璃在侵蚀过程中的铅析出速率和表面形貌等进行了测定。研究结果表明,铅水晶玻璃在不同溶液中长时间浸泡会导致铅析出,析出量和析出速率与其Pb_3O_4质量分数有关,其中低、中铅玻璃相对稳定,高铅玻璃的铅析出量大幅提升。     

Orientation Effect of the Wafer on the Structural Properties of P+ Type Porous Silicon Layers

The structural properties of (111) oriented p⁺ type Porous Silicon (PS) samples are investigated using various X-ray diffraction techniques and compared to (001) p⁺ type PS layer structure. High resolution X-ray diffractometry was used to record rocking curves and reciprocal space maps, giving indications about the crystalline quality of the PS samples as well as about the pore orientation. X-ray diffraction and reflectivity performed on thin PS layers allow to estimate the layer thickness, porosity and roughness of the PS/substrate interface.