Research Of Copper Interconnection Technology For Three-dimensional Package

In the semiconductor industry, integration of chips is dominated by Moore’s Law.However, with the feature sizes of the chip approaching the physical limits,costs torealize minimization become higher, which brings difficult in following Moore’s Law. Theemergence of3D integration and packaging technologies are expected to overcome thesetechnical bottlenecks for the continuation of Moore’s Law. This prospect attracts researchinstitutions’ sights on3D integration and packaging technologies. Bonding technology is akey realize3D integration and packaging. Based on numbers of bonding technologies,copper bonding is able to accomplish electrical communication between chips, besidesthe excellent thermal conductivity and signal transmission performance is the currenthotspot. In this paper, copper bonding theoretical analysis and experimental research wereinvestigated under the background of the dimensional integration and packaging, based onwhich the high-density copper bump interconnect technology were studied. The maincontents and results are as follows:Hot diffusion bonding model diffusion method was set based on the mechanism Thekey technical difficulties bonded copper were analyzed according to the pressing diffusionbonding experimental results: copper surface oxidation and contamination. Copperbonding using l-hexanethiol self-assembled monolayer on the copper surface passivationprotection was adopted to deal with these difficulties. The passivation effect of1-hexanethiol was attained by measuring the contact angle. The detection result of thebonding showed that: l-hexanethiol has a good passivation effect which can efficientlyprotect the surface of copper and be applied to3D integration technologies.The convex copper interconnect technology was explored based on copper bondingmechanism and convex point high-density interconnect technology. Copper convex pointbonding process and procedures were designed, and experimental studies of its keytechnology were carried out. Experimental analysis of the results were obtained tooptimize process parameters to realize a high-quality, high-density copper convex pointsamples diffusion bonding. SAM, SEM detection results showed that: in most of thebonding samples, micro bumps present in regular shapes, and arranged in neat. Littlebubbles and spinous appeared, which confirmed that this process can be applied to theconvex point interconnect technology.