This overview focuses on the different types of noise occurring in deep submicrometer silicon metal oxide semiconductor field- effect transistors and their use as an analytical tool. The noise sources comprise white noise, generation- recombination noise, random telegraph signal fluctuations, and 1/ f or flicker noise. The fundamental basis of each noise type is briefly described and illustrated by some practical examples. In a second part, the impact of the properties of the silicon substrate ( orientation, crystallization technique, silicon- on- insulator, SiGe) on the noise performance is discussed. Finally, the influence on the low-frequency noise behavior of different advanced process modules, such as gate stack, device isolation, silicidation, and gate engineering, is illustrated. (C) 2004 The Electrochemical Society.