Variability of Low Frequency Noise and mismatch in enclosed-gate and standard nMOSFETs

Variability of Low Frequency Noise (LFN) and Random Telegraph Noise (RTN) is an important concern for many analog CMOS integrated circuits. In this paper, transistors with enclosed gate layout are examined and compared with standard layout transistors, with particular emphasis on weak inversion region. Enclosed gate transistors show an improved gate voltage mismatch in weak inversion. A compact MOSFET model for LFN and its variability, based on number fluctuation theory, is shown to cover well the behavior of either type of transistors. Lower levels of noise as well as lower variability of noise are observed in enclosed gate transistors.