Threshold Voltage Control through Multiple Supply Voltages for Power-Efficient FinFET Interconnects

In modern circuits, interconnect efficiency is a central determinant of circuit efficiency. Moreover, as technology is scaled down, the importance of efficient interconnect design is increasing. In this paper, we explore an option for low-power interconnect synthesis at the 32 nm node and beyond, using fin-type field-effect transistors (FinFETs) which are a promising substitute for bulk CMOS at the considered gate lengths. We consider a previously-unexplored mechanism for improving FinFET efficiency, called threshold voltage control through multiple supply voltages (TCMS), which is significantly different from conventional multiple-supply voltage schemes. We develop a circuit design for a FinFET buffer using TCMS. We describe a variation of van Ginneken's classic dynamic programming framework for solving the problem of power-optimal TCMS buffer insertion on a given routing tree. We show that, on an average, TCMS can provide power savings of 50.41% and device area savings of 9.17% compared to a state-of-the-art dual-Vdd interconnect synthesis scheme.