Change of 1/f noise in MOSFETS due to degradation

Hot-carrier stress in n-channel MOSFETs was investigated. A negative shift in the threshold voltage and a decrease in the drain current were observed. In addition, the degradation increases the series resistance on the drain side. In most cases, the relative 1/f noise in the drain current also increases. The change in the dc characteristics and the 1/f noise indicates that the damage is localised on the drain side for a long-channel device, while it extends along the channel towards the source for a short-channel device. A degraded device is often found to be noisier in its reverse mode than in its normal mode.