Optimal doping elements for inhibiting surface-diffusion of adatoms on Cu3Sn
Optimal doping elements for inhibiting surface-diffusion of adatoms on Cu3Sn
复制标题
抑制Cu3Sn吸附原子表面扩散的最佳掺杂元素
DOI：
10.1016/j.apsusc.2022.155003
复制
发表时间：
2023-01
影响因子：
6.7
通讯作者：
Guang Chen
中科院分区：
文献类型：
--
作者：
Wenjie Dai;Yang Chen;Xu Liu;Henggao Xiang;Chi Xu;Gong Zheng;Guang Chen
三维集成电路（3D-IC）中微凸块的向下缩放会导致横向Cu 3Sn的形成，从而导致严重的可靠性问题。在固态时效过程中抑制Cu和Sn的连续表面扩散是抑制横向Cu 3Sn生长的关键。在此，通过全面的密度泛函理论计算，我们发现Ti和Si是抑制表面扩散的理想表面掺杂元素。Ti和Si的掺杂不仅显著增加了Cu和Sn原子在其附近的扩散势垒，而且降低了表面原子的迁移率。通过电子结构和晶体轨道汉密尔顿布居分析，我们揭示了潜在的机制是在相邻的吸附位上的Cu和Sn吸附原子的结合增强和Ti和Si与表面的强共价键合。此外，发现掺杂Ti对Sn吸附原子的表面扩散的阻碍作用远大于Cu吸附原子，而掺杂Si对Cu吸附原子的表面扩散的阻碍作用大于Sn吸附原子。这项工作揭示了利用金属间化合物表面掺杂元素有效抑制表面扩散和降低3D-IC可靠性风险的可能性。
Downward scaling of the micro-bumps in three-dimensional integrated circuits (3D-ICs) aggravates the formation of lateral Cu3Sn causing serious reliability issues. Inhibiting the continuous surface diffusion of Cu and Sn during solid-state aging is critical to suppress the growth of lateral Cu3Sn. Herein, through comprehensive density functional theory calculations, we found Ti and Si are the ideal surface doping elements for suppressing surface diffusion. The doping Ti and Si not only significantly increase the diffusion barriers of Cu and Sn adatoms in their vicinity but also reduce the mobility of the surface atoms. Through electronic structure and crystal orbital Hamilton population analysis, we reveal the underlying mechanism is the enhanced binding of Cu and Sn adatoms in neighboring adsorption sites and strong covalent bonding of Ti and Si with the surface. Moreover, it is found doping Ti impedes the surface diffusion of Sn adatoms much more greatly than Cu adatoms while doping Si hinders the surface diffusion of Cu adatoms rather than Sn adatoms. This work sheds light on the possibility of utilizing doping elements on intermetallic compound surface to effectively inhibit surface diffusion and reduce reliability risks in 3D-ICs.
登录
查看更多内容
影响因子：
2.1
作者：
Chao-Kun Hu;D. Canaperi;Shyng-Tsong Chen;L. Gignac;S. Kaldor;M. Krishnan;S. G. Malhotra;E. Liniger;J. Lloyd;D. Rath;D. Restaino;R. Rosenberg;J. Rubino;S. Seo;A. Simon;S. Smith;W. Tseng
通讯作者：
Chao-Kun Hu;D. Canaperi;Shyng-Tsong Chen;L. Gignac;S. Kaldor;M. Krishnan;S. G. Malhotra;E. Liniger;J. Lloyd;D. Rath;D. Restaino;R. Rosenberg;J. Rubino;S. Seo;A. Simon;S. Smith;W. Tseng
影响因子：
17.6
作者：
Jie Xu;Hua Dong;Jun Xi;Yingguo Yang;Yue Yu;Lin Ma;Jinbo Chen;B. Jiao;X. Hou;Jingrui Li-Jingru
通讯作者：
Jie Xu;Hua Dong;Jun Xi;Yingguo Yang;Yue Yu;Lin Ma;Jinbo Chen;B. Jiao;X. Hou;Jingrui Li-Jingru
影响因子：
4.6
作者：
H. W. Yang;J. Y. Wu;Z. X. Zhu;C. Kao
通讯作者：
H. W. Yang;J. Y. Wu;Z. X. Zhu;C. Kao
影响因子：
3.7
作者：
Kresse, G;Furthmuller, J
通讯作者：
Furthmuller, J
影响因子：
8.6
作者：
Uberuaga;Leskovar;Smith;Jónsson;Olmstead
通讯作者：
Uberuaga;Leskovar;Smith;Jónsson;Olmstead