This chapter focuses on double gate (DG) Tunneling Field Effect Transistor (TFET), having band engineering and high - k dielectrics. The basic structure of TFET device is derived and developed by p-i-n diode, containing two heavily doped degenerated semiconductor “p” and “n” regions and lightly doped intrinsic “i” region, respectively. The chapter explores the idea of high-k dielectric engineering as well as band engineering concept with DG -TFET. TFET is a type of field effect device in which current transport phenomena occur due to quantum tunneling between source and channel. The estimation of device characteristics and performance of TFET is time consuming and costly due to lack of rapid advancement in technology. TFET devices have become the most popular switching device among semiconductor players. The chapter summarizes the obtained results by popular device analysis technique, modeling and simulation of DG -TFET.

Dopant diffusion in semiconductors is a very important in process step of device. diffusion has a great influence on the electrical and electronic properties especially in the lacunary and interstitial mechanismis. This chapter investigates the diffusion of P and B in Si. The profiles have been simulated using Secondary Ion Mass Spectrometry (SIMS) modele [1,2]. In the process for manufacturing MOS transistor, the manufacturers follow basically three steps. The starting substrate is a monocrystalline silicon wafer. The first step consists in producing the polysilicon gate on a thin layer of SiO2 followed by implantation (boron) of the gate. The second step is the training of source-drain junctions by ion implantation to high dose (≈ 10 15 at / cm2) and the third is to silicide the source-drain junctions for reduce the contact resistance. One of the most promising silicides is the monosilicide of nickel (NiSi). therefore, it is very important to understand the redistribution of dopants in the different active parts of a transistor by studying the following points: • The redistribution of boron in polycrystalline silicon (gate), • The redistribution of boron in the monocrystal

In recent years, the design and fabrication ofmulti-gate Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) have attracted more efforts due to their high appropriateness for advanced integration circuits' applications. In fact, the boost of MOSFET structures is a battle against parasitic phenomena appearing at the nanoscale level. Short channel and quantum confinement effects are among the critical drawbacks that need to be remedied carefully. On the other hand, the hot carrier degradation effect is mainly a reliability concern affecting the device per- formance after long duration of work. In response to the high computational costs related to the development of physi- cal based models for Double Gate (DG) MOSFETs including all these effects, more flexible alternatives have been proposed for the prediction of device performances. Our aim in this chapter is to investigate the efficiency of a new proposed frame- work, built upon Kriging metamodeling and Non-dominated Sorting Genetic Algorithm version II (NSGA II), for the optimal design in terms of OFF-current, threshold voltage and swing factor. The input variables of interest are limited to the geometrical parameters namely the channel length and thickness. Data generated according to computer experiments, based on ATLAS 2-D simulator, are used to identify and adjust Kriging surrogate models. It is emphasized that the obtained models can be used accurately in a multi-objective context to offer several Pareto optimal configurations. Therefore, a wide range of selection possibilities is avail- able to the designer depending on situations under consideration.