Analysis of the interactions of HCD under “On” and “Off” state modes for 28nm FDSOI AC RF modelling

New Modelling Off-state TDDB for 130nm to 28nm CMOS nodes

“…Nevertheless, ∆IdLin during HCD Off mode in 65 and 130 nm CMOS nodes has known to not recover on the removal of the stress conditions [5], probably due to the lack of ultra-thin gate-oxide defects. In [1] interaction between HCD On-state and HCD off-state on 28FDSOI NFET has been evidenced by alternating DC sequences as previously done in [18] showing a history effect when charges are captured in silicon dangling bonds at interface during Off-state. This interaction between HCD…”

“…Time dynamics also differ between On and Off states HCD since this follows under Off mode a logarithmic time dependence commonly reported as to be due to hot-holes trapping (like under NBTI [17]) in N-channel case device. In our previous work [1] we had performed relaxation phases by alternating fresh Off-state sequence to recovery phase at VDS = VGS = 0V and that showed generation of permanent defects (NIT) and recoverable one. This implies trapped/detrapped charge in stressed interface layer under oxide on scaled device.…”

“…HCD in On-state was carried out using pre-stress step following On-state TDDB tests showing neither reduction nor acceleration of TBD [12]. However, we observed recently that pre-stress HCD under multiple particle mechanism (MP) can lead to TBD reduction under Off mode TDDB compared to fresh TDDB [1,2].…”

“…Illustration of tBD laws according to(1) with EA, β, VAF and LAF parameters. β and VAF are higher under Off-state TDDB in contrast to EA related to the largest β extracted in PMOS device and VAF in NMOS device.…”

Device Reliability to Circuit Qualification: Insights and Challenges

“…Under HCD "Off-state" stress, ΔIdLin measured under subthreshold regime is plotted (Fig. 5) showing positive increase with time and following a logarithmic law dependence [30]. In this case the damage doesn't exceed 10%, which might be related to ≡Si─O bonds excitation and breaking due to hole trapping.…”