Bumpless interconnect of Cu electrodes in millions-pins level
Bumpless interconnect of Cu electrodes in millions-pins level
复制标题
数百万引脚级铜电极的无凸块互连
DOI：
10.1109/ectc.2006.1645808
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
T. Suga
中科院分区：
文献类型：
--
作者：
A. Shigetou;T. Itoh;T. Suga
在本研究中，我们利用表面活化键合（SAB）方法在晶圆尺度上实现了百万针级铜电极的无凹凸互连。无凹凸互连是补偿热膨胀失配以获得微米级键合间距的有效方法，超低轮廓铜电极在低加热温度下直接键合，从而获得较高的对准精度和可靠性。为了实现晶圆级互连，采用光刻工艺和化学机械抛光工艺在8英寸和6英寸晶圆上制备了1250万个尺寸为10倍30mum2、间隔为10mum的电极。为了明确适合CMP-Cu的SAB条件，以保证表面的清洁度和平整度，从而获得优异的粘接质量，我们对表面清洗和真空条件进行了修改。采用SAB晶圆键合机进行键合实验，在真空条件下实现了微米级的全晶圆对准精度，所有电极在约2.0倍10- 4n /pin的接触载荷下成功互连。整个晶圆的对中偏差低至2mum，抗剪强度可大于70MPa
In this study, we demonstrated the bumpless interconnect of Cu electrodes in millions-pins level in the wafer-scale by means of the surface activated bonding (SAB) method. The bumpless interconnect is a highly effective way to compensate the thermal expansion mismatch to obtain the bonding pitch of microns where ultra-low profiled Cu electrodes are bonded directly at low heating temperature to achieve high alignment accuracy and reliability. For the realization of wafer-scale interconnection, 12.5 million electrodes with the dimensions of 10times30mum2 and intervals of 10mum were fabricated on 8 and 6-inch wafers by the photolithography followed by the CMP (chemical mechanical polishing) process. In order to clarify appropriate SAB conditions for CMP-Cu to ensure both the cleanness and flatness of the surface to obtain an excellent quality of bonding, we modified the surface cleaning and vacuum conditions. The bonding experiments were performed with the SAB wafer bonder that enables the alignment accuracy of microns all over the wafer in the vacuum condition, and all electrodes were successfully interconnected with the contact load of around 2.0times10-4N/pin. The misalignment turned out as low as 2mum in the entire wafer, and the shear strength could be larger than 70MPa