Subsurface damage and bending strength analysis for ultra-thin and flexible silicon chips
Subsurface damage and bending strength analysis for ultra-thin and flexible silicon chips
复制标题
超薄柔性硅芯片的次表面损伤和弯曲强度分析
DOI：
10.1007/s11431-021-2021-4
复制
发表时间：
2022-07-18
影响因子：
4.6
通讯作者：
Feng Xue
中科院分区：
文献类型：
--
作者：
Jian Wei;Wang ZhaoXian;Feng Xue
亚表面损伤（SSD）是制备超薄柔性硅片的精密机械研磨过程中不可避免的问题。目前，对不同磨削参数下超薄切屑的SSD与抗弯强度之间关系的研究相对较少。在这项研究中，SSD包括非晶化和位错观察使用透射电子显微镜。不同工艺参数引起的SSD深度的理论预测与实验数据吻合良好。磨削深度增加的主要原因是磨粒尺寸的增大、进给速度的加快和砂轮转速的降低。采用三点弯曲试验对不同磨削条件下的超薄切屑的抗弯强度进行了测试。结果表明，提高砂轮转速、减小磨粒粒度和进给量，均能有效地降低磨削深度，从而提高切屑的抗弯强度。湿法蚀刻和化学机械抛光（CMP）分别用于去除由研磨引起的SSD，并且两者都有助于提供更高的弯曲强度，但是相比之下，CMP由于光滑的表面轮廓而工作得更好。本研究旨在为优化磨削工艺、制备具有较高抗弯强度的超薄切屑提供一定的指导。
Subsurface damage (SSD) is an unavoidable problem in the precision mechanical grinding for preparing ultra-thin and flexible silicon chips. At present, there are relatively few studies on the relationship between SSD and the bending strength of ultra-thin chips under different grinding parameters. In this study, SSD including amorphization and dislocation is observed using a transmission electron microscope. Theoretical predictions of the SSD depth induced by different processing parameters are in good agreement with experimental data. The main reasons for SSD depth increase include the increase of grit size, the acceleration of feed rate, and the slowdown of wheel rotation speed. Three-point bending test is adopted to measure the bending strength of ultra-thin chips processed by different grinding conditions. The results show that increasing wheel rotation speed and decreasing grit size and feed rate will improve the bending strength of chips, due to the reduction of SSD depth. Wet etching and chemical mechanical polishing (CMP) are applied respectively to remove the SSD induced by grinding, and both contribute to providing a higher bending strength, but in comparison, CMP works better due to a smooth surface profile. This research aims to provide some guidance for optimizing the grinding process and fabricating ultra-thin chips with higher bending strength.