1/f noise in advanced CMOS transistors

Complementary metal-oxide-semiconductor (CMOS) technology is dominant in the microelectronics industry for a wide range of applications, including analog, digital, RF, and sensor systems. The advantages of silicon CMOS technology compared to bipolar technology as well as transistors in other semiconductors is well-established. CMOS technology scaling has been a main drive for continuous progress in the silicon based semiconductor industry over the past two decades [1]. The continuous downscaling of CMOS technologies towards nano feature size has increased the performance of integrated circuits considerably. However, one important limitation of MOSFET downscaling is an increase of 1/f noise (often referred to as low-frequency noise), since the 1/f noise increases as the reciprocal of the device area [2], [3]. Furthermore, the development of nano-sized CMOS technologies has led to the observation of random telegraph signals (RTS) [4] yielding large low frequency current fluctuations. Excessive low-frequency noise introduces serious limitations on the functionality of analog and digital circuits since it deteriorates the noise figure of operational amplifiers and A/D and D/A converters. Lowfrequency noise diminishes the signal-to-noise-ratio (SNR) of CMOS sensors, such as IR or CMOS image sensors [5] [6]. The 1/f noise is also of paramount importance in RF circuit applications where it gives rise to phase noise in oscillators or multiplexers [7]. The 1/f noise is a sensitive diagnostic tool to monitor radiation effects on MOSFETs [8].