LOW-FREQUENCY NOISE CHARACTERIZATION OF 0.18 MU-M SI CMOS TRANSISTORS

The low frequency (LF) noise and random telegraph signal (RTS) fluctua tions in 0.18 mu m complementary metal-oxide-semiconductor (CMOS) devi ces are investigated. We find that the 1/f noise stems from fluctuatio ns in the carrier number of both N and P channel MOS devices. The slow oxide trap concentration deduced from the noise data is approximate t o 10(17)/eV cm(3) in agreement with previous 0.35 to 0.25 mu m technol ogies and state-of-the-art gate oxides. The study of some particular R TSs is performed and provides the gate voltage dependence of the captu re/emission times as well as of the drain current RTS amplitude. Drain current RTS amplitudes as large as 5 to 10% have been observed, being somewhat larger than for 0.35 to 0.25 mu m CMOS technologies. In addi tion, the dispersion of the noise level measured at a fixed biasing cu rrent and frequency is investigated as a function of the device gate a rea, showing a considerable large sample-to-sample variation for the s mallest devices. Finally, the residual noise backgrounding the RTS noi se is studied as a function of gate voltage for some RTSs and is found to be a white noise presumably associated to RTSs with higher cut-off frequencies.