Total-Ionizing-Dose Effects and Low-Frequency Noise in 30-nm Gate-Length Bulk and SOI FinFETs with SiO₂/HfO₂ Gate Dielectrics

Abstract

Due to the advances in manufacturing and enhanced gate control of the transistor channel, FinFETs are commonly used in highly-scaled ICs. The geometry of the devices is one of the key factors impacting radiation responses of FinFETs. This thesis presents results of total-ionizing-dose irradiation and low-frequency noise of 30-nm gate-length bulk and SOI FinFETs for devices with fin widths of 10 nm to 40 nm. Minimal threshold voltage shifts are observed at 2 Mrad(SiO₂), but large increases in low-frequency noise are found, and significant changes in defect-energy distributions are inferred. Radiation-induced leakage current is enhanced for narrow- and short-channel bulk FinFETs. Short-channel SOI FinFETs show enhanced degradation compared with longer-channel devices. Narrow- and short-channel SOI devices exhibit high radiation tolerance. Significant random telegraph noise is observed in smaller devices due to prominent individual defects.