Low-frequency noise modelling and measurements in submicrometer MOSFETs processed in 0.7 μm CMOS technology

Engineering interest in the low-frequency noise behaviour of submicrometer MOSFETs is first of all driven by analogue applications such as image active pixel sensor, where noise minimisation is a key issue and often defines the sensitivity or detection limit. In this paper a simple model for low-frequency noise in submicrometer MOSFETs is presented. Expressions for the normalised spectral density of the drain current fluctuations S1d/Id2 are derived on the basis of a theory that incorporates both the oxide-trap-induced carrier number and mobility fluctuation mechanisms. The latter is attributed to the Coulomb scattering effect of the fluctuating occupied oxide-trap. Next, a measurement technique as well as experimental results of N-channel MOSFETs processed in 0.7 μm CMOS technology are presented. The low-frequency noise is measured from weak to strong inversion, and from linear to non-linear region. Also, RTS noise in submicrometer N-channel MOSFETs at weak inversion mode for linear region is investigated.