Impact of BEOL Design on Self-heating and Reliability in Highly-scaled FinFETs

Abstract

This paper investigates the impact of BEOL design on device and backend reliability – HCI, BTI, EM – due to dependence of self-heating on BEOL in highly-scaled FinFETs. Our analysis indicates that due to poor thermal coupling to substrate – in the thin fin body devices – a large part of heat flows out of BEOL. This makes self-heating, and thus device (FEOL) temperature, very sensitive to BEOL design. The heat flow through BEOL also significantly increases the metal and via temperatures. The increased temperature negatively affects the overall reliability, and one of the ways to mitigate device degradation is optimization of BEOL design.