Dissertation Defense: Kan Li, Interdisciplinary Materials Science
DISSERTATION DEFENSE
Kan Li, Interdisciplinary Materials Science
*under the direction of Dr. Ronald Schrimpf
“Laser-induced single event effects, total-ionizing-dose effects, and low-frequency noise in advanced FinFETs”
Tuesday, May 24, 2022 | 12:00 | Zoom
In this dissertation, radiation effects and low-frequency noise are studied in advanced FinFETs. Firstly, we evaluate the single-event effects on devices with the promising InGaAs channel material and highly-scaled fin widths (sub-10 nm) through pulsed-laser measurements. Higher peak currents and greater charge collection are observed in wider fin devices as a result of larger active volumes. The amplitudes of the SETs and the collected charge also increase with Vds due to the enhancement of the electric field along the channel; the transient tail increases as the overdrive voltage increases. Charge collection is influenced strongly by the shunt effect and parasitic bipolar effect. Secondly, we investigate total-ionizing-dose (TID) response and low-frequency noise in bulk Si FinFETs with/without through-silicon vias (TSVs) integration. TSVs negligibly impact charge trapping properties of gate/field oxides during TID, or the 1/f noise results, and nMOS and pMOS devices show opposite border-trap energy distribution trends at room temperature. Temperature dependence of 1/f noise is also explored in both device types with SiO2/HfO2 gate dielectrics. The nMOSFET 1/f noise generally decreases as temperature increases, with three prominent individual defect-related peaks detected, while pMOSFET 1/f noise generally increases with increasing temperature with no peaks observed. The gate-voltage dependence of noise at different temperatures shows a qualitatively consistent result with that inferred from Dutta-Horn analysis of the temperature dependence of the noise.