Generation and distribution of residual stress during nano-grinding of monocrystalline silicon-猫眼课题宝

单晶硅纳米磨削过程中残余应力的产生与分布

DOI：

10.7567/jjap.57.121302

发表时间：

2018-11

期刊：

Japanese Journal of Applied Physics

影响因子：

1.5

通讯作者：

中科院分区：

物理与天体物理4区

文献类型：

作者：

Pei Chen;Zhiwei Zhang;Tong An;Huiping Yu;Fei Qin

单晶硅在磨削过程中产生的残余应力会导致硅片翘曲变形，给后续的夹持、划片等工艺带来困难。它还可能导致裂纹的形成和腐蚀的发生，这对硅元件的电气性能是有害的。采用共焦激光显微拉曼光谱技术，研究了阶梯线湿法腐蚀工艺下磨削硅片中残余应力的相变和分布。随着刻蚀深度的减小，残余应力呈现出压应力减小、张应力分散分布的趋势。采用分子动力学模拟方法对单晶硅纳米磨削过程中残余应力的产生机理进行了研究。观察到相变硅形式的亚表面损伤（SSD），并且SSD的深度随切削深度而变化。通过对相变硅体积收缩的研究，解释了硅磨削的机理和磨削后产生残余应力的原因。采用Stony理论和分子动力学结果中的非晶相体积收缩率，建立了一个理论模型，确定了硅衬底亚表面压应力的变化趋势。

Residual stress generated in grinding process of monocrystalline silicon can cause the wafer warpage, and difficulties in subsequent processes such as holding and scribing. It can also lead to the formation of cracks and the occurrence of corrosion, which is harmful for electrical performance of silicon component. In this study, with the method of step-wire wet etching, the phase transformation and distribution of residual stress in ground silicon wafer were examined by confocal laser micro-Raman spectroscopy. As the etching depth going down, the residual stress exhibits in the trends of decreasing of compressive stress and following a scatter distribution of tensile stress. During the nano-grinding processes of monocrystalline silicon, the generation mechanism of residual stress is computed by a series of the molecular dynamic (MD) simulation. Subsurface damage (SSD) in the form of phase-transformed silicon is observed, and the depth of SSD varies by the depth of cut. The volume shrinkage of phase-transformed silicon is also studied to explain the grinding mechanism and the reason for inducing residual stress of ground silicon. By adopted the Stony theory and volume shrinkage rate of amorphous phase from MD results, a theoretical model is established to determine the trend of compressive stress in subsurface of ground silicon.