Effects of Post CF₄ Plasma Treatment on the HfO₂ Thin Film

Abstract

In this study, a novel approach was proposed to improve the characterization of HfO 2 . Fluorine was incorporated by CF 4 plasma to improve the HfO 2 gate dielectric properties including leakage current, breakdown voltage and hysteresis. The hysteresis of capacitance-voltage characteristics can be reduced to approximately 10% hysteresis voltage for the samples with CF 4 plasma treatment. An inner-interface trapping model is presented to explain the hysteresis. The secondary-ion mass spectroscopy (SIMS) results show that there is a significant incorporation of fluorine (F) at the interface between the HfO 2 thin film and silicon substrate. The incorporation of F effectively suppressed leakage current and improved carrier trapping without an increase in interfacial layer thickness.

Self-Passivation by Fluorine Plasma Treatment and Low-Temperature Annealing in SiGe Nanowires for Biochemical Sensors

“…The sensitivity of the nanowire sample posttreated with N 2 is higher than those of nanowire samples posttreated with NH 3 and those that did not receive treatment. Several studies have reported the successful incorporation of nitrogen into the interfacial layer (IL) and dielectric layer of high-material [33][34][35][36]. Hence, plasma treatment was effective for incorporating nitrogen on the SiGe nanowire surface.…”

Reliability Properties and Current Conduction Mechanisms of HfO2 MIS Capacitor with Dual Plasma Treatment

“…On the other hand, the capacitance density and interface characteristics show further improvement with the combination of CF 4 pre-treatment for 10 sec and N 2 post-treatment for 120 sec. With CF 4 pre-treatment, fluorine atoms would pile up at the HfO 2 /Si interface, improve the quality of interface [19], and suppress the IL formation [20]. Besides, for CF 4 pre-treatment times longer than 10 sec, the plasma damage caused the degradation of HfO 2 /Si interface and the degradation of capacitance density.…”

Effects of fluorine incorporation into HfO2 gate dielectrics on InP and In0.53Ga0.47As metal-oxide-semiconductor field-effect-transistors

“…[13][14][15][16][17][18] It has been reported that on Si substrate, F tends to segregate to the HfO 2 / SiO 2 and SiO 2 / Si interfaces passivating oxygen vacancy and interface traps by forming stronger Hf-F and Si-F bonds. 13 On Ge substrate, formation of Ge-F and Hf-F bonds at the high / Ge interface and in the HfO 2 gate dielectric results in less interface and bulk traps, respectively.…”

“…Insufficient plasma treatment might not improve the gate dielectric quality, and excessive plasma treatment possibly causes plasma damage and corrodes the improvement. 17,18 Figure 3 compares the SS and hysteresis for the HfO 2 / InP gate stack with different CF 4 rf powers for 3 min. SS for the control sample, samples with 20 W treatment, and samples with 30 W treatment are 120 mV/dec, 106.6 mV/dec, and 97.1 mV/dec, respectively.…”