On the feasability of through-wafer optical interconnects for hybrid-WSI architectures.

The desire to acheive a high degree of parallelism WSI and H-WSI architectures has stimulated study of three dimensional interconnect structures, obtained by stacking wafer circuit boards and providing interconnections both in the plane of each board as well as vertically between wafers over the entire wafer area. Aside from the well known communication advantages, using free-space optical links for these vertical interconnects is also appealing since no mechanical interconnects exist to fatigue or fail during assembly or thermal cycling.