Comprehensive study of gate-terminated and source-terminated field-plate 0.13 νm NMOS transistors

This study systematically investigated microwave noise, power and linearity characteristics of field-plate (FP) 0.13 νm CMOS transistors in which the field-plate metal is connected to the gate terminal and the source terminal. The gate-terminated FP NMOS (FP-G NMOS) provided the best noise figure (NF) at 6 GHz compared with standard devices and the source-terminated FP device (FP-S NMOS) as the lowest gate resistance (R_g) was obtained by this structure. By adopting the field-plate metal in NMOS, both FP-S and FP-G devices achieved higher current density at high gate bias voltages. Moreover, these two devices also had higher efficiency under high drain-to-source voltages at the high input power swing. The third-order inter-modulation product (IM3) is -39.4 dBm for FP-S NMOS at P_in of -20 dBm; the corresponding values for FP-G and standard devices are -34.9 dBm and -37.3 dBm, respectively. Experimental results indicate that the FP-G architecture is suitable for low noise applications and FP-S is suitable for high power and high linearity operation.