击穿法降低3D电子封装侧壁布线接触电阻的研究  

Reducing contact resistance of sidewall interconnect in 3D electronic package by breakdown method

作　　者：奚锐 王旭 王心语 董显平[1] 李明[1] XI Rui;WANG Xu;WANG Xinyu;DONG Xianping;LI Ming(School of Material Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;San Disk Information Technology Co.,Ltd.,Shanghai 200241,China)

机构地区：[1]上海交通大学材料科学与工程学院,上海200240 [2]晟碟信息科技有限公司,上海200241

出　　处：《电子元件与材料》2024年第8期980-987,共8页Electronic Components And Materials

摘　　要：由于工艺原因,以侧壁布线为互连方式的3D封装结构,其侧壁再布线端头表面不可避免地会产生一层铜氧化膜,导致互连界面接触电阻升高。采用击穿法处理不同前处理条件下的样品,通过X射线能谱、选区电子衍射、高分辨透射显微镜对样品击穿后的互连界面进行了表征。结果表明:对于在不同烘烤环境、烘烤时长和清洁工艺下制备的样品,击穿法均可实现95%以上的降阻效果,并将接触电阻均降至1Ω以下。其中采用真空烘烤10 h并进行等离子处理制备的样品,在经过击穿处理后,样品的接触电阻达到最低,为0.26Ω。击穿法通过在铜氧化膜处施加电场,使铜离子沿电场方向迁移,随后还原为多晶的Cu和Cu_(2)O,形成低电阻的导电通路,从而降低互连界面的接触电阻。说明击穿法适用于降低侧壁互连工艺中互连界面的接触电阻。Due to the process issues,3D package structures with sidewall interconnect inevitably produce a copper oxide layer on the surface of the sidewall redistribution stubs,which results in higher contact resistance at the interconnect interface.The samples processed under different pre-treatment conditions were analyzed using the breakdown method.The interconnect interface of the samples after breakdown was characterized by X-ray spectroscopy,selected area electron diffraction,and high-resolution transmission microscopy.The results show that the breakdown method can achieve a resistance reduction effect of over 95%for the samples prepared under different baking environments,baking time,and cleaning processes.Additionally,the contact resistance is reduced to below 1Ωin all cases.The contact resistance of the sample,prepared by vacuum baking,baking for 10 hours,and plasma treatment,reaches a minimum of 0.26Ωafter the breakdown treatment.With the breakdown method,the contact resistance of the interconnect interface is reduced by applying an electric field to the copper oxide layer.As a result,the copper ions migrates along the direction of the electric field and is reduced to polycrystalline Cu and Cu_(2)O,forming a low-resistance conductive path.It is shown that the breakdown method is suitable for reducing the contact resistance of the interconnect interface in the sidewall interconnect process.

关 键 词：3D封装 侧壁布线 互连界面 铜氧化膜 接触电阻 击穿 

分 类 号：TN405.97[电子电信—微电子学与固体电子学]