Low-Frequency-Noise Investigation of n-Channel Bulk FinFETs Developed for One-Transistor Memory Cells

The low frequency (LF) noise has been studied in n-channel triple-gate bulk fin Field-Effect Transistors (FinFETs), which are developed for one-transistor (1T) memory applications. Significant variation in the noise spectral density has been observed, which is related to the random occurrence of excess Lorentzian components, associated with generation-recombination (GR) noise. Both gate-voltage-dependent and gate-voltage-independent GR noise peaks have been found, which are assigned to gate oxide traps or traps in the silicon fins, respectively. In addition, excess 1/f noise in weak inversion has sometimes been observed and is ascribed to surface-roughness fluctuations. Overall, the gate oxide quality seems to be the major contributor to the LF noise and not the channel and source-drain engineering investigated here.