Does NBTI effect in MOS transistors depend on channel length?

Negative bias temperature instability (NBTI) has been examined on p-MOSFET and n-MOSFET with different channel lengths. The experiments have shown a channel length dependence on NBTI-degradation, indicating inhomogeneous distribution of NBTI-induced traps along the channel. Simulation results, using SILVACO 2D TCAD tools, have revealed that the degradation is mainly located in the lightly doped drain (LDD) region. Interestingly, simulation results have exhibited the presence of a breakpoint, below which the degradation in the effective channel dominates that of the LDD region and vice versa.