Hot-carrier-induced off-state leakage (HCIOL) currents were successfully used as a new monitor in characterizing device reliability. HCIOL current increases drastically with reducing channel length, but the stress bias only affects the onset time of HCIOL current. For buried-channel PMOSFET's, only the HCIOL currents at the reverse measurement configuration were dominant. However, in surface-channel devices, HCIOL currents at both forward and reverse configurations became important. An empirical HCIOL current model was developed to quantify device lifetime as a function of channel length and stress voltage. Estimated lifetime results indicated that HCIOL current will impose a major limit on device reliability especially for deep-submicrometer technology and low power applications.