Compact Physics Hot-Carrier Degradation Model Valid over a Wide Bias Range

Abstract

We develop a compact physics model for hot-carrier degradation (HCD) that is valid over a wide range of gate and drain voltages (Vgs and Vds, respectively). Special attention is paid to the contribution of secondary carriers (generated by impact ionization) to HCD, which was shown to be significant under stress conditions with low Vgs and relatively high Vds. Implementation of this contribution is based on refined modeling of carrier transport for both primary and secondary carriers. To validate the model, we employ foundry-quality n-channel transistors and a broad range of stress voltages {Vgs,Vds}.

The Understanding and Compact Modeling of Reliability in Modern Metal–Oxide–Semiconductor Field-Effect Transistors: From Single-Mode to Mixed-Mode Mechanisms

“…As shown in Figure 1 , taking a typical inverter circuit as an example, devices undergo three typical biasing conditions: gate voltage (V gs ) > 0 V, drain voltage (V ds ) = 0 V; |V gs | > 0 V, |V ds | > 0 V and V gs = 0 V, |V ds | > 0 V. The degradation phenomena observed in NMOS or PMOS devices under the bias condition of |V gs | > 0 V, V ds = 0 V are, respectively, termed positive bias temperature instability (PBTI) [ 24 , 25 , 26 ] and negative bias temperature instability (NBTI) [ 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. The degradation phenomenon observed when the device is under the bias condition of |V gs | > 0 V, |V ds | > 0 V is referred to as hot carrier degradation (HCD) [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. The degradation observed under the bias condition of V gs = 0 V, |V ds | > 0 V is termed off-state degradation (OSD) [ 42 , 43 , 44 ].…”