Impact of High-k Dielectric Materials on Short Channel Effects in Tri-gate SOI FinFETs

The CMOS technology has been dominated long enough by the silicon material world and it has been approaching to its limitations. With contracting magnitudes of thicknesses of the gate oxide layer, leakage current worsens which drastically reduces the device reliability. In the nano regime device, the introduction of high-k materials has brought down the Short Channel Effects (SCEs) significantly. They also provide electrical stability and have proven to be scalable. Different devices are evolved for different gate oxides such as SiO2 and high-k materials like Si3N4, Al2O3, ZrO2 and HfO2. These high-k dielectric materials are compared with the performance of SiO2 in a Tri-Gate (TG) SOI FinFET device. TG SOI FinFETs with 14, 10 and 8 nm gate lengths are implemented for all the dielectric materials considering an equivalent oxide thickness of 1 nm for SiO2. Since the devices are developed in the nano regime, the parameters relating to SCEs such as the roll-off of threshold voltage, on-to-off current ratio and DIBL are investigated and analyzed for all the TG SOI FinFETs. Observation of the electrical characteristics of the devices led to the culmination that the Ion current is at the same level for all geometrical gate lengths. But the leakage currents reduced drastically with HfO2 as the gate dielectric material rendering the highest switching speed of the device along with excellent control over the short channel parameters. The results inevitably show that high-k dielectric material based devices provide enhanced performance by reducing the leakage current, thereby attaining degradation in the SCEs. It has also been perceived that the HfO2 based TG SOI FinFET is found to be the most superior among all others even at 8 nm channel length.