The flicker noise behavior of MOSFETs fabricated by different technologies were characterized. It was found that the technology has very significant effects on the noise characteristics and that all the results can be explained within a unified framework with an oxide trap density distribution. Hot-carrier stressing of n-channel MOSFETs can result in a very large increase of flicker noise, whereas for p-channel MOSFETs the noise is hardly affected. Random telegraph noise is observed in some deep-submicron MOSFETs with very small channel area. A detailed analysis of the telegraph noise suggests that the mobility fluctuation induced by charge trapping plays an important role in the origin of the flicker noise. A novel flicker-noise model incorporating both carrier number and mobility fluctuations is proposed.<<ETX>>