Comparison of microwave performances for sub-quarter micron fully- and partially-depleted SOI MOSFETs

The high frequency performances including microwave noise parameters for sub-quarter micron fully- (FD and partially-depleted (PD) silicon-on-insulator (SOI) n-MOSFETs are described and compared. Direct extraction techniques based on the physical meaning of each small-signal and noise model element are used to extract the microwave characteristics of various FD and PD SOI n-MOSFETs with different channel lenghts and widths. TiSi2 silicidation process has been demonstrated very efficient to reduce the sheet and contact resistances of gate, source and drain transistor regions. 0.25 žm FD SOI n-MOSFETs with a total gate width of 100 žm present a state-of-the-art minimum noise figure of 0.8 dB and high associated gain of 13 dB at 6 GHz for V(ds) = 0.75 V and P(dc) < 3 mW. A maximum extrapolated oscillation frequency of about 70 GHz has been obtained at V(ds) = 1 V and J(ds) = 100 mA/mm. This new generation of MOSFETs presents very good analogical and digital high speed performances with a low power consumption which make them extremely attractive for high frequency portable applications such as the wireless communications.