Design of High-Speed Interconnects for 3D/2.5D ICs without TSVs
Transistor scaling has developed the semiconductor industry over the last few decades. However, as the lithography process approaches its limit, research and development cost for a new technology node has increased dramatically. 3D integration has been considered as a promising solution for continuously improving transistor count per area and system performance. Through-silicon via (TSV) technology is the most popular integration technology. However, it has several issues to be addressed such as thermal issues, mechanical stress, high fabrication cost, and placement issues. Several alternative interconnect technologies such as inductive coupling interconnect, capacitive coupling interconnect, and silicon interposer have been introduced.
This chapter will introduce various design techniques utilizing these alternative interconnect methods. First, transceiver design using inductive coupling will be discussed. Several design techniques will be introduced. Second, how to design capacitive coupling interconnect will be explained. Various challenges such as alignment, cross talk, and transceiver design will be covered. Finally, high-speed interconnect utilizing silicon interposer (known as 2.5D) will be briefly explained as an intermediate interconnect technology between conventional PCB and TSV.