3-Dimensional Integration with High Interconnection Density

A conventional 2-dimensional scaling down seems to reach its fundamental limits. Further increasing areal integration density required a significant investment of time and money as the dimension of the devices becomes close to those of molecules. On the other hand, the systems that has been requested lately should require more functions to be incorporated in a constrained space. Therefore, 3-dimensional stacking of device layers has attracted attention. To take over 2D scaling of system-on-chip approach, 3D integration should have high density of interconnection density. In this talk, 3D integration for high interconnect density technologies would be addressed. Monolithic 3D is a sequential 3D integration technique to stack multiple device that was proposed to increase integration density and decrease the signal delay and power consumption by reducing interconnection length. Hybrid bonding is a parallel 3D integration technique having a dielectric bond with embedded metal to form interconnections. Higher connectivity can be accomplished because solder bumps on dies are not required to make connections. However, to adopt these technologies, it is necessary to develop novel process techniques and study several technical issues.