Impact of Backside Power Delivery Network with Buried Power Rails on Latch-up Immunity in DTCO/STCO

In this work, the impact of buried power rail (BPR) on latch-up (LU) immunity is discussed. Measurement and simulation results indicate an increase in LU immunity by inserting BPR which brings the feature of blocking the current path. Furthermore, the differences in current gain product with different BPR biases including Vss, Vdd, -Vdd, and their difference in location, namely p-type well (PW) and n-type well (NW) are covered. The appropriate bias further increases LU immunity however the inappropriately applied voltage to the BPR lines compared to the well bias induces unexpected LU risk.