Power Transfer Methods for Inductively Coupled 3-D ICs

The advent of Internet of Things (IoT) has created novel opportunities for integrated systems. Envisioned IoT applications in healthcare, well-being, entertainment, structural monitoring and other domains will require integrated systems that incorporate all different combinations of sensing, acquisition, and processing modules each manufactured in the most suitable process node. An enabling technology for supporting these systems is three-dimensional (3-D) integration where multiple physical tiers are integrated to form a multi-tier stack [1].

3-D integrated circuits typically use through silicon vias (TSV) for electrical inter-tier connectivity. These solutions, however, are still very expensive and technologically challenging, especially for heterogeneous designs where TSVs between tiers fabricated in different process nodes are required. Wireless connectivity through magnetic field, on the other hand, can circumvent these limitations providing cost-efficient solutions for inter-tier communication [2], [3] and sufficient power delivery [4]. Designing these wireless inductive links is a challenging approach, due to strict area and power constraints, therefore awaiting new ideas that will result in efficient power transfer techniques and reliable data exchange schemes.
This research project aims specifically the topic of power transfer between tiers for sensor driven applications. The design space for these power transfer components is multi-dimensional depending upon the power transfer method, e.g., inductive coupling or magnetic resonance, area, power demand, physical distance between the tiers, sensor EM sensitivity, etc. This complex design space presents unique opportunities for novel circuit design techniques and optimization methodologies for a diversity of objectives such as system performance, cost/area, noise, and inter-tier bandwidth. Tradeoffs among physical parameters for the on-chip inductors and different circuit designs should be explored leading potentially to several link designs with different traits, offering greater insight in the design of highly heterogeneous contactless vertical systems. This project will build on existing expertise recently developed in the group in the design of inter-tier communication links. Test circuits to measure the efficiency of the proposed ideas will be fabricated through multi-project wafer services and the student will also have the opportunity to gain experience in testing of ICs in addition to design and simulation methods.

[1] V. F. Pavlidis, I. Savidis, and E. G. Friedman, Three-Dimensional Integrated Circuit Design, 2nd Edition, Morgan Kaufmann Publishers, June 2017.
[2] I. Papistas and V. F. Pavlidis, "Contactless Inter-Tier Communication for Heterogeneous 3-D ICs," Proceedings of the IEEE International Symposium on Circuits and Systems, pp. 2585-2588, May 2017.
[3] I. Papistas and V. F. Pavlidis, "Inter-Tier Crosstalk Noise on Power Delivery Networks for 3-D ICs with Inductively-Coupled Interconnects," Proceedings of the ACM/IEEE Great Lakes Symposium on VLSI, pp. 257-262, May 2016.
[4] S. Han and D. Wentzloff, "Wireless Power Transfer Using Resonant Inductive Coupling for 3D Integrated ICs," Proceedings of the IEEE International 3D Systems Integration Conference, pp. 1-5, November 2010.