The study of Cu-Cu low temperature bonding using formic acid treatment with/without Pt catalyst
The study of Cu-Cu low temperature bonding using formic acid treatment with/without Pt catalyst
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DOI：
10.1109/icept.2016.7583247
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发表时间：
2016-08
期刊：
影响因子：
--
通讯作者：
Wenhua Yang;Yangting Lu;Suga Tadatomo
中科院分区：
文献类型：
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作者：
Wenhua Yang;Yangting Lu;Suga Tadatomo
Cu低温键合是实现高性能三维互连的重要技术之一。为了去除铜膜表面的氧化物和污染物，实现低温键合，提出了一种甲酸蒸汽处理工艺对铜膜表面进行处理，使铜膜表面洁净。在这项研究中，铜样品表面处理甲酸蒸气与铂或没有铂催化剂。通过XPS表面分析发现，甲酸蒸气处理使Cu样品表面氧化物还原，Pt催化剂的加入使Cu样品表面氧化物还原。然而，还原的效果对于有/没有Pt是不同的。用铂催化剂处理甲酸蒸气的效果优于不加铂催化剂的甲酸蒸气处理。为了测量铜电极的接触电阻和键合强度，设计并制作了一种新型的低温键合铜电极样品。Cu电极键合在200°C下分别使用具有Pt催化剂和不具有Pt催化剂的甲酸处理进行。用Pt催化剂处理的粘结强度比不加Pt催化剂处理的粘结强度高，约为40 MPa。
Cu low temperature bonding is one of important technologies for high performance 3-D interconnection. In order to remove Cu surface oxide and contaminations for low temperature bonding, formic acid vapor treatment process was proposed to treat Cu film surface for clean Cu surface. In this study, Cu sample surfaces were treated by formic acid vapor with Pt or without Pt catalyst. Through XPS surface analysis, it is found that Cu sample surface oxide was reduced by formic acid vapor treatment with/without Pt catalyst. However, the effect of reduction is different for with/without Pt. The effect of formic acid vapor treatment with Pt catalyst is better than that without Pt catalyst. In order to measure the contact resistance and bonding strength, a new type Cu electrodes sample was designed and fabricated for low temperature bonding. Cu electrodes bondings were performed at 200°C using formic acid treatment with Pt catalyst and without Pt catalyst, respectively. For he treatment with Pt catalyst, the bonding is stronger than that without Pt catalyst, and the strength is about 40Mpa.