Trap Parameter Extraction Method for FinFET Based on Random Telegraph Noise at Cryogenic Temperatures

This work presents a comprehensive analysis of random telegraph noise (RTN) in 16-/14-nm node n- and p-FinFETs at cryogenic temperatures (down to 10 K). Experimental observations reveal two-level RTN signals originating from charge trapping/detrapping at individual traps. The gate-voltage dependence of RTN time constants uncovers fundamental limitations of the classical Shockley-Read-Hall (SRH) theory at cryogenic temperatures, as extracted trap parameters exhibit unphysical temperature dependence. To address this, a novel parameter extraction methodology grounded in nonradiative multiphonon (NMP) theory is developed, incorporating trap energy level, spatial location, relaxation energy, and lattice displacement. The NMP framework resolves the inconsistencies of SRH theory by accounting for lattice vibrational energy broadening and statistical physical properties under cryogenic conditions. Contrary to the conventional view that cryogenic RTN defects predominantly reside at the channel interface, validation across temperatures confirms that the n-FinFET defect is located at the SiO₂/HfO₂ interface and the p-FinFET defect in the SiO₂ layer, both positioned away from the channel interface. This approach enables temperature-independent and physically consistent defect characterization, advancing the understanding of oxide traps in nanoscale FinFETs and establishing a robust methodology for cryogenic reliability analysis.