EFFECTS OF SCALING OF JUNCTIONLESS TRANSISTOR PARAMETERS WITH SILICON DIOXIDE (SIO2) AND SILICON NITRATE (SI3N4) GATE OXIDES ON THE ELECTRICAL CHARACTERISTICS OF THE DEVICES

Abstract

This research investigated the effects of scaling of parameters of junctionless transistors (JLT) with SiO₂ gate oxide and Si₃N₄ gate oxide on the electrical characteristics of the two devices. It also compared the electrical performance of the two devices as a way of replacing the conventional SiO₂ gate oxide with high-k dielectric such as Si₃N₄ gate oxide. Different JLT were designed and simulated using a technology computer aided device software, sentaurus and extracted the electrical characteristics such as Threshold voltage, subthreshold slope, drain induced barrier lowering, on-state current etc. It was observed that leakage current, DIBL, SS as well as on-state current were significantly improved using Si₃N₄ as gate oxide in JLT. As a result, on-state to off-state current ratio was greatly increased, hence the speed of the device. The performance was significantly increased to approximately 10⁹ using Si₃N₄ material for gate length of 10nm and nanowire diameter of 10nm. All these were achieved because of the high dielectric constant, k of the Si₃N₄ which is higher than that of SiO₂. Similarly, Si₃N₄ has also has high energy band gap which considerably help in reducing the leakage current and other short channel effects (SCEs).