AbstractThis paper addresses hot-carrier related reliability issues in deep submicron silicon nMOSFET devices. In order to monitor the hot-carrier induced device degradation, the substrate current was measured for devices with varying channel lengths (20 um - 0.24 um) under various biasing conditions. Deep submicron devices experience velocity saturation of channel carriers due to extremely high lateral electric fields. To evaluate the effects of velocity saturation in the channel, the pinch-off length in the channel was extracted for all the devices of the target technology. It was observed that for very short channel devices, carriers in most of the channel experience velocity saturation and almost the entire channel gets pinched off. It is shown in this paper that for very short channel devices, the pinch-off length in the channel is limited by the effective channel length, and that velocity saturation effects are critical to the transport of channel carriers.
