倒装芯片封装中多层铜互连结构的界面分层  

Interface Delamination of Multilayer Copper Interconnect Structure in Flip-Chip Packaging

作　　者：黄慧霞 张立文 杨贺 杨陈 曹磊 李团飞 Huang Huixia;Zhang Liwen;Yang He;Yang Chen;Cao Lei;Li Tuanfei(College of Information Engineering,Henan University of Science and Technology,Luoyang 471023,China;Luoyang Science and Technology Innovation Promotion and Information Research Center,Luoyang 471000,China)

机构地区：[1]河南科技大学信息工程学院,河南洛阳471023 [2]洛阳市科技创新促进和情报研究中心,河南洛阳471000

出　　处：《半导体技术》2023年第3期255-261,267,共8页Semiconductor Technology

基　　金：河南省重点研发与推广专项(科技攻关)项目(222102210207);河南省高等学校重点科研项目(20B510006)。

摘　　要：芯片封装过程中,较高的机械热应力易导致多层铜互连结构发生分层甚至断裂失效。运用三级子模型技术建立了倒装芯片10层铜互连结构的有限元分析模型,通过计算不同界面裂纹尖端能量释放率对多层铜互连结构的界面分层展开研究。结果表明:第10层Cu/SiN和金属间电介质(IMD)/SiN界面,以及第9层Cu/SiN界面的裂纹尖端能量释放率远大于其他界面,是易发生分层失效的关键界面;总体互连线介电材料的弹性模量和热膨胀系数对关键界面能量释放率都有影响。基于此分析,对总体互连线介电材料的选取进行优化,发现第10层选择弹性模量与热膨胀系数乘积最大的非掺杂硅玻璃(USG),第9层选择弹性模量与热膨胀系数乘积最小的有机硅酸盐玻璃(OSG)时更有利于提高多层铜互连结构界面可靠性。A high thermo-mechanical stress may lead to delamination,even fracture failure in multilayer Cu interconnect structure during chip packaging.Three-level sub-modeling technology was used to build a finite element analysis model of 10-layer Cu interconnect structure in Flip-Chip packaging.The interface delamination of multilayer Cu interconnect structure was studied by calculating energy release rates at different interface crack tips.The results show that the energy release rates of crack tips of Cu/SiN interface and inter-media dielectric(IMD)/SiN interfaces in layer 10,and Cu/SiN interface in layer 9 are much higher than that of other interfaces,which are critical interfaces and prone to delamination failure.The energy release rates of critical interfaces are affected by both elastic modulus and thermal expansion coefficient of the dielectric material in the global interconnect line.Based on the analysis,the selection of the global interconnection dielectric material was optimized.It is found that un-doped silicate glass(USG)with the largest product value of elastic modulus and thermal expansion coefficient as the dielectric material of layer 10 and organosilicate glass(OSG)with the smallest product value of elastic modulus and thermal expansion coefficient as dielectric material of layer 9 are better for improving the reliability of multilayer Cu interconnect structure.

关 键 词：铜互连结构 子模型技术 界面分层 能量释放率 介电材料 

分 类 号：TN405.97[电子电信—微电子学与固体电子学]