3D INTEGRATED CIRCUITS
The paper deals with 3D-IC''s,there is saying in the real estate: When land gets expensive, multistored buildings are the alternative solution. We have similar situation in the chip industry. For the past 30 years, chip designers have considered whether building integrated circuits multiple layers might create cheaper,powerful chips. With shorter interconnects in 3D''s, both switching energy and cycle time are expected to be reduced. Many options are available for realization of 3D circuits. The choice of fabrication depends on the requirement of circuit system. The demand for EDA tools increase as the technology matures. 3D standard cell tool design has three parts: 1) 3D cell placement by min-cut partitioning. 2) 3D global routing (inter - wafer vias) circuit layout management (MAGIC). Analysis of Thermal problems in 3d is necessary to evaluate thermal robustness of different 3D technology and design options. In multi-layer circuits, the heat generation increases linearly with increase in levels.Thus measures are to be taken in order to reduce failure mechanisms. shorter wire lengths help reduce the inductance. Electro thermal and Thermo mechanical effects between various active layers can influence electro - migration and chip performance Die yields issues may arise due to mismatches between die yields of different layers, which affect net yield of 3D chips. Implications on Circuit Design and Architecture includes: 1) Buffer Insertion 2) Layout of critical paths. 3) Microprocessor design 4) Mixed signal IC''s 5) Physical design and synthesis. Thus " We are at the door step of the largest shift in the semi- conductor industry ever, one that will dwarf the PC and even the consumer electronics eras." "The core element needed to usher in the new age will be a complex integration of different types of devices such as memory, logic, sensor, processor and software, together with new materials, and advanced die stack technologies,.....all based on silicon technology"
Writers....G.V.PRATAP REDDY G.KAVITHA
Summary by ..R.Krishna kumar