| Abstract | A fundamental shift in the technology has occurred beyond 90nm CMOS where the interconnect resistance has been increasing significantly to cause a repeater explosion problem. This problem translates into not only significant area overhead but also power, as repeaters lose power to leakage. 3D technology has the potential of easing the challenge of repeater explosion. In order to exploit the full potential of 3D technology, new challenges in the area of physical design, thermal analysis, system level design and analysis need to be addressed. 3D interconnects have the potential of reducing critical paths delays significantly, which are typically between memory and the interfacing logic. New tools that consider thermally aware physical design implementations, most importantly at the architecture and SoC level are crucial to the success of 3D as thermal issues are exacerbated in 3D implementations. To justify the cost and complexity overhead of 3D technology, it is essential to study the benefit of 3D early in the design cycle. This requires strong linkage between architecture level analysis tools and 3D physical planning tools. Most of the advantages of 3D will be utilized with new system architectures and physical implementations. Therefore, the tools to aid 3D implementation must also operate at the higher level in addition to the 3D place and route algorithms that have been proposed in the literature before. In fact, the benefits from 3D place and route will be limited since current 2D designs do a fairly good job of optimizing the critical path distance.
There is a very strong need for 3D architectural and physical planning tools that operate in the domain of thermal, physical, and performance analysis in order to yield an optimized system implementation in 3D technology. Most of the studies reporting huge benefits from 3D for wire length do not adequately consider the physical impact of vertical vias. It is crucial to consider the impact of vertical vias on the physical design of ICs, from area, latency, and thermal impact point of view. |