Characterization of self-heating leads to universal scaling of HCI degradation of multi-fin SOI FinFETs

Abstract

SOI FinFETs and other Gate-all-around (GAA) transistors topologies have excellent 3-D electrostatic control and therefore, have been suggested as potential technology options for sub-14 nm technology nodes. Unfortunately, the narrow gate geometry and reduced gate pitch suppress heat dissipation and increase thermal cross-talk, leading to severe self-heating of these transistors. Self-heating degrades performance and makes the classical reliability theories based on T_L~T_sub irrelevant. In this paper, first, we propose a physics-based thermal circuit compact model for multi-fin SOI FinFETs to characterize self-heating and validate the results by AC conductance method. Next, we analyze HCI degradation varying with the number of fin (N_fin), chuck temperature (T_sub) and AC frequency (f). The results show that HCI degradation dependent variables (N_FIN, T_sub, f) can be correlated to the lattice temperature (T_L = g(N_FIN, T_sub, f)) and obey the universal degradation curve (ΔV_th(T_L) = f(S(T_L) × t)). Si-O bond-dispersion model explains the universal curve; therefore, the model can be used for a long term reliability projection with arbitrary combination N_fin, T_sub, f, etc.