Analysis of Gate-voltage Dependence of RF Inductive Effect Parameters in Equivalent Circuit for Floating Body PD-SOI MOSFETs

The dependence of the effective inductance L_k and RF kink resistance R_k on V_GS, which model RF inductive effect in floating body PD-SOI MOSFETs with L_g=0.1㎛, is physically analyzed for the first time after these parameters are directly extracted from the measured S-parameters. L_k and R_k decrease with increasing V_GS because L_k is inversely proportional to the body transconductance g_mb and impact ionization conductance g_mi and R_k is also inversely proportional to g_mb. Using physically induced equations, it is confirmed that the rise of g_mi at a higher V_GS occurs because the increase of I_DS is more prevalent than the decrease of the impact ionization multiplication factor in the short-channel device of L_g=0.1㎛, and the increase of g_mb at a higher V_GS is mainly caused by the increase of the transconductance and internal body voltage. The V_GS-dependence of L_k and R_k is verified by observing the increase in extracted g_mi and g_mb data when V_GS becomes higher using S-parameter optimization based on a physical equivalent circuit.