STUDY AND MODELING OF SINGLE AND MULTI LAYER GRAPHENE FIELD EFFECT TRANSISTOR STRUCTURES WITH VARIOUS DIELECTRIC

Abstract

A transistor is the most important component of computer and electronic devices, which is facing the problem of performance limitations of conventional Integrated circuits, as it is the biggest challenge for the electronics, semiconductor industry and information technology. The reduction of dimensions in silicon-based transistors faces great challenges as dimensions approach atomic sizes and physical limits will be eventually reached. A great deal of research has been centred on new 2-D material graphene that can overcome these limitations. Thus, to make our computers smart and fast we have to replace the silicon material with graphene, it has enormous electrical conductivity and many research’s almost in every space of life has proved graphene as the material of the future. The Discovery of graphene raises the prospect of a new class of nanoelectronics devices based on the extraordinary physical properties of this one-atom-thick layer of carbon. Unlike other two-dimensional electron layers in semiconductors, where the charge carriers become immobile at low densities, the carrier mobility in graphene can remain high, even when their density vanishes at the Dirac point. The high electron mobility of graphene (200000 cm2 V-1 S-1 ) [1] makes graphene-based field effect transistors (GFETs) excellent candidates for replacing silicon-based nanometer Complementary Metal Oxide Semiconductor (CMOS). High transconductance gain (gm) and saturation region for GFETs drain current facilitates the use of GFETs as a voltage-controlled current source and the design of analog circuits. Until now, drain current saturation has been observed in long gate GFET devices, but now short gate also presents unsatisfying current saturation behavior, Bilayer graphene comes out as an alternate and improves the current 2 saturation behavior for GFET Devices. Lateral graphene heterostructure is another solution for current saturation improvement for high-frequency GFETs. Some of the physical models have been developed by the researcher, which does not have closed expressions and so need numerical methods and expressions which avail us of simple mathematical models for different parameters for GFETs. Since Graphene is a miracle material which has extraordinary properties: like high mobility, very high thermal conductivity, optically transparent, and stability at the atomic level. It is the two-dimensional single atomic layer of 0.342 nm thickness. It is stronger than steel and even lighter in weight. This material is of importance and interest that a European organization named graphene flagship is fabricating and integrating ICs at the industrial level named by 2D-Experimental Plot line (EPL). Figure 1.1 graphene electronics product from the fabrication lab to market MGFET-4D, MGFET-4P, and GFET S20 chip from Graphenea. GFET-S20 contains 36 GFETs applicable for sensing applications.