基于分子动力学的硅晶圆均匀减薄磨削研究  

Uniformly thinning grinding of silicon wafers based on molecular dynamics

作　　者：黄绍服[1] 吴义城 赵茂俞 HUANG Shaofu;WU Yicheng;ZHAO Maoyu(School of Electromechanical Engineering,Anhui University of Science and Technology,Huainan 232001,CHN;Fundamental Experiment and Training Center,Hefei University,Hefei 230601,CHN)

机构地区：[1]安徽理工大学机电工程学院,安徽淮南232001 [2]合肥大学基础实验与实训中心,安徽合肥230601

出　　处：《制造技术与机床》2025年第1期133-140,共8页Manufacturing Technology & Machine Tool

基　　金：合肥市自然科学基金项目(2022025)。

摘　　要：超精密减薄磨削加工是半导体硅晶圆制造的关键工艺环节之一。然而,亚表面裂纹、残余应力和微结构的晶格畸变是减薄磨削产生的主要损伤缺陷。通过硅晶圆的减薄磨削,研究等效应变和残余应力的分布,评价磨削损伤。首先,分别建立球形和三棱锥单颗粒金刚石磨削硅晶圆的分子动力学模拟模型,应用Lammps模拟软件,设计硅晶圆转速、砂轮转速、磨削量为工艺参数,模拟硅晶圆减薄磨削。其次,获得硅晶圆表面的应变、等效应变分布数据。将磨削时硅晶格上原子发生形变相对位移值作为损伤评价目标,计算损伤值。在此基础上,在φ300 mm硅晶圆磨削后样品上的7个位置上,分别进行10 mm×10 mm×0.3 mm的取样,应用Roman光谱仪,测试、获得每个取样点处的平均残余应力。进一步,通过硅晶圆磨削的模拟和试验测试,获得了不同位置各X、Y、Z方向应变、等效应变和残余应力的分布,结果显示硅晶圆表面的等效应变相差8.1%,残余应力相差9%。最终,表明该磨削的等效应变、残余应力分布均匀,工艺参数合理、可行,可为硅晶圆的超精密、高效减薄磨削加工提供理论依据。Ultra-precision thinning and grinding is one of the key processes in semiconductor silicon wafer manufacture.However,subsurface cracks,residual stresses and microstructural lattice distortions are the main damage defects generated by thinning grinding.Through the thinning grinding of silicon wafers,the distributions of effective strain and residual stress were studied to evaluate the grinding damage.Firstly,the molecular dynamics simulation models of grinding silicon wafers with spherical and trigonal single-grain diamonds were established respectively.The process parameters of the silicon wafer rotational speed,grinding wheel rotational speed,and removing volume were selected to simulate the grinding by the Lammps software.Secondly,the strain and equivalent strain distribution data on the surface of the silicon wafer were obtained.The value of relative displacement of atoms deformed on the silicon lattice during grinding was taken as the damage evaluation object,and the damage value was calculated.On this basis,the size of 10 mm×10 mm×0.3 mm samples were taken at seven positions on theϕ300 mm silicon wafer after grinding,and Roman spectrometer was employed to test and obtain the average residual stress at the sample points.Further,the distribution of strain,equivalent strain and residual stress in X,Y and Z direction at different positions were attained by investigating of the simulation and experimental test of the grinding.The results demonstrate that the equivalent strain values on the surface of silicon wafer differed by 8.1%,and the residual stress values differed by 9%.Finally,it shows that the equivalent strain and residual stress of the grinding are uniformly distribution,and the process parameters are reasonable and feasible,which can provide theoretical basis for the ultra-precision and high-efficiency thinning grinding processing of silicon wafers.

关 键 词：硅晶圆 分子动力学仿真 磨削 应变 残余应力 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]