Measurement and Modeling of Drain Current Thermal Noise to Shot Noise Ratio in 90nm CMOS

We present here experimental measurement and modeling of drain current thermal noise in a 90 nm CMOS technology, with a focus on its current dependence. For the first time we show experimental evidence that drain current noise in weak inversion is indeed shot-like (2ql). In saturation, drain current noise is mainly determined by the drain current, and only weakly dependent on the drain voltage. A simple model of noise is derived and compared with data. The model enables noise estimation from only DC I-V curves, and yields excellent agreement with measurement for PMOS, and acceptable agreement for NMOS.