Subsurface damage and bending strength analysis for ultra-thin and flexible silicon chips  

作　　者：JIAN Wei WANG ZhaoXian JIN Peng ZHU Longji CHEN Ying FENG Xue 

机构地区：[1]Key Laboratory of Applied Mechanics of Ministry of Education,Department of Engineering Mechanics,Tsinghua University,Beijing100084,China [2]Center for Flexible Electronics Technology,Tsinghua University,Bejing 100084,China [3]Institute of Flexible Electronics Technology of Tsinghua University Jiaxing,Jiaxing314000,China [4]Qiantang Scienceand Technology Innovation Center,Hangzhou310016,China

出　　处：《Science China(Technological Sciences)》2023年第1期215-222,共8页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. U20A6001, 11625207, 11902292, and 11921002);the Zhejiang Province Key Research and Development Project (Grant Nos.2019C05002, 2020C05004, and 2021C01183)。

摘　　要：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.

关 键 词：ultra-thin chip flexible chip subsurface damage bending strength mechanical grinding 

分 类 号：TG1[金属学及工艺—金属学]