Wireless Interconnect Using Inductive Coupling in 3DICs

The mobile market is growing rapidly, as is the demand for high
performance and multiple functions in a single device. 3D integration is a promising solution for integrating heterogeneous ICs in a single device since it can achieve a small form-factor and high performance systems with low power by stacking multiple die vertically and using through-wafer
interconnects between the layers. There are several methods proposed to implement vertical links in 3DICs. TSVs are one of the most promising methods because they allow high-bandwidth and high-density interconnect and low power dissipation without increasing silicon area. Another promising method is wireless interconnect using inductive coupling. This has the advantages of not only high data rates and low power, but is compatibility
all conventional planar IC processes.

This thesis provides circuit solutions to implement vertical
interconnects for 3DICs. It characterizes the wireless inductive coupling channel and proposes two circuit techniques to enhance its performance. Resonant Inductive Coupling (RIC) can improve the efficiency of inductive data and power links. Furthermore, the combination of in-phase RIC and regenerative oscillation is shown to effectively boost the received signals in multi-layer stacking. Two prototypes are fabricated to demonstrate inductive data links, and one prototype is fabricated of an inductive power link.