IJRECE VOL. 6 ISSUE 4 ( OCTOBER- DECEMBER 2018) ISSN: 2393-9028 (PRINT) | ISSN: 2348-2281 (ONLINE) INTERNATIONAL JOURNAL OF RESEARCH IN ELECTRONICS AND COMPUTER ENGINEERING A UNIT OF I2OR 797 | Page Design and Simulation of Charge Transport in Single Electron Transistor Using Tcad Numerical Simulator Tarun Singhal 1 , Vijay K. Lamba 2 , Javed Ashraf 3 1 Research Scholar, ECE, AFSET, Faridabad (Haryana) India, 2 Professor, Global college of Engineering, Ropar (Punjab) India, 3 Professor, ALFLAH University Abstract- The ability to control the flow of electron of a MOSFET is decreased due to quantum mechanical effect when scaled down below 50 nm .To compete this challenge a new field of device research is needed. One such area is devices based on tunneling phenomena called as single electron devices. In this paper a most fundamental single electron device, single electron transistor (SET) is designed using visual TCAD with gate length of 2nm and gate width of 2nm. The channel is ultra thin with length of 2nm and width of .005 nm and channel thickness is .3nm.Then a Si quantum dot of size .5*1.6nm2 is used between the island and gate. Both the Devices are simulated using Genius Simulator successfully. It is found that at room temperature the device with Si dot is more promising. Device with Si dot have less capacitance and higher charging energy than device without Quantum dot. Keywords- Quantum tunneling, Coulomb blockade (CB), quantum dot (QD), single electron transistor (SET). I. INTRODUCTION The manipulation of single electrons was demonstrated by Millikan in the beginning of 20th century by Millikan. In the late 1980s it was implemented for solid state circuits because its reproducible fabrication is required for small size conducting particles, and their exact place averse to external electrodes. The growth in techniques of nanofabrication in the last three decades facilitates a new branch of solid state physics called single-electronics [1]. SET is essential in single electronics where the device operation depends on the effect of Coulomb blockade and can be designed at very small scale. However, the voltage gain provided by SET is low, input impedances is high and it is sensitive to background charges [1]. SETs can take the electronics industry to the theoretical limit of electrons for computing applications. It allows representation of logic state by using single electron [2]. The SET can be used for the metrology and memory applications. It can be used as supersensitive electrometers and primary thermometers [2]. II. SINGLE ELECTRON TRANSISTOR(SET) SET have been designed with small dimensions of few nanometers using semiconductors, metals and individual molecules. It made up of a tiny conducting island which is coupled with source and drain guided by tunnel junctions and coupled capacitively to gates. Fig.1: Geometry of SET [3]. a. SET Operation The addition or withdrawal of only one electron can change the electrostatic or Coulomb energy in a mesoscopic system. A mesoscopic system is Quantum dot [QD] in which Coulomb energy is more than the thermal energy and can manage the transportation of electron inside and outside of the QD. This responsiveness to a single electron has open on to electronics which is based on individual electrons. As shown in figure 2.2 a nanoparticle of metal is placed between electrodes of metal. For separation of particle from electrodes insulation layer of oxide or vacuum can be used. This separation allows only tunneling of electron between them. The junctions between nanoparticles and electrodes can be modeled as a resistor and capacitor in parallel. The value of capacitance is dependent on particle size and value of resistance depends on tunneling of electrons. The capacitors and resistors are denoted by C1, C2, R1 and R2. The applied voltage between electrodes is denoted by V. Now it will be discussed that how the current, depends on applied voltage V. Fig.2: Quantum Dot structures [4]. When we increase applied voltage from zero, there is no current flow between two electrodes because for movement of