Analysis on Variations of Metal Gate Work Function on Junctionless Double Gate MOSFET with High-k Spacers

Abstract

The fabrication of nanometer-scale traditional MOSFETs with junctions has become very challenging. The newer devices like junction less double gate MOSFETs are in focus as they have shown good electrostatic behavior compared with traditional MOSFETs. In this paper, we introduce new device architecture with high-k spacers placed on either side of both the gates of a junctionless double gate MOSFET. The effect of the high dielectric constant (ksp) of the spacer on the device characteristics has been studied. This paper investigates the junctionless double gate MOSFETs with high-k spacers of materials like silicon dioxide (SiO2), hafnium oxide (HfO2) and aluminum oxide (Al2O3). One of the important considerations for selecting the particular metal gate material is metal work function as it directly affects threshold voltage and the performance of the transistor. The work is done on the device to carry out analysis for drain induced barrier lowering (DIBL), output characteristics, transfer characteristics and ION/ IOFF ratio.