Study of Impact of HfO2 gate oxide on the Electrical Characteristics of Nanowire Junction less Transistor

Abstract

This paper proposes hafnium (IV) oxide (HfO₂) as gate oxide material of the nanowire junctionless transistor (NJT) to replace conventional silicon dioxide (SiO₂). Leakage current usually increased due to an increase of tunneling of electrons in the SiO₂ transistor when the thickness oxide (t_ox) of the gate material is below 2nm. The main advantage of HfO₂ is a high dielectric constant k of 20 to 25 which is almost 6 times that of SiO₂. Similarly, HfO₂ has an energy band gap of 5.3 to 5.7eV. As a result, low leakage current and short channel effects (SCEs) were experienced. An increase in the gate capacitance of the device leads to improving the performance of the device without affecting the enhanced leakage current. All these were achieved by designing and simulating the device using the SDE tools of Sentaurus TCAD. Electrical characteristics were extracted using the Service tools of the software. The performance was significantly increased to approximately 10¹⁰ using HfO₂ material.