Flicker Noise Characterization of LDMOS In Finfet Technology

The flicker noise (1/f noise) behavior of FinFET LDMOS (Lateral Double-diffused MOS) transistor varies significantly from that of a conventional MOS transistor because of the extended drain region in LDMOS. Therefore, through an investigation of a 14 nm FinFET LDMOS, two distinct phenomena were discovered, discussed and first reported in this paper. Firstly, the trend of the Sid vs. Vd (drain voltage) curves was studied. The Sid vs. Vd curves exhibited an increase with drain voltage at relatively low drain voltage, then followed by a significant drop once the drain voltage reached a certain value. Space Charge Modulation (SCM) and hot spot formation theories were employed to interpret the mechanism behind this trend and this trend was linked to Quasi-saturation (QS) effect in LDMOS. Secondly, the unparalleled Sid vs. Frequency curves due to the existence of the extended drain in the LDMOS were studied. On the basis of this finding, a new BSIM-CMG LDMOS subcircuit model was proposed, which consisted a MOS transistor and a terminal voltage dependent resistor. SPICE simulation results revealed that this subcircuit model was able to accurately describe the noise behavior of the FinFET LDMOS and could be applied to tremendous fields where LDMOS plays a role.