Hot-carrier degradation phenomena in n-channel MOSFETs (NMOSFETs) through the comparison between conventional and lightly doped drain (LDD) structure of 0.8-mum CMOS technology was described. This phenomenon was also observed in the conventional NMOSFETs. This is because of hot-electron trap in the gate accumulating carriers (holes) along the channel region near the drain. That is, these holes effectively increased the effective channel length. On the other hand, the lifetimes of conventional and LDD NMOSFETs defined as how long it takes the transconductance deviation to reach 10 %, which the LDD NMOSFETs are longer than conventional NMOSFETs under the same hot-carrier condition.