Three-dimensional (3D) integration is clearly the simplest answer to most of the semiconductor industry s vexing problems: heterogeneous integration and red- tions of power, form factor, delay, and even cost. Conceptually the power, latency, and form factor of a system with a ?xed number of transistors all scale roughly linearly with the diameter of the smallest sphere enclosing frequently interacting devices. This clearly provides the fundamental motivation behind 3D technologies which vertically stack several strata of device and interconnect layers with high vertical interconnectivity. In...

Three-dimensional (3D) integration is clearly the simplest answer to most of the semiconductor industry s vexing problems: heterogeneous integration and red- tions of power, form factor, delay, and even cost. Conceptually the power, latency, and form factor of a system with a ?xed number of transistors all scale roughly linearly with the diameter of the smallest sphere enclosing frequently interacting devices. This clearly provides the fundamental motivation behind 3D technologies which vertically stack several strata of device and interconnect layers with high vertical interconnectivity. In...