Bøger af Swapnadip De

In this book the main focus has been on the modeling and the influence of depletion layers around the source and the drain regions on the sub-threshold characteristics of a short channel MOS transistor with uniformly-doped channel. An analytical model for sub-threshold surface potential in a short channel MOS transistor has been developed by solving the pseduo-2D Poisson¿s equation, formulated by applying Gauss¿s law to a rectangular box in the channel covering the entire depletion layer depth. The model has been able to predict an increased influence of the junction depletion regions for smaller channel length and/or higher drain/source bias voltages due to increased charge sharing. The same model is applied to find the sub threshold surface potential for Double Halo MOSFETs. The shrinking of device dimension leads to reduction of gate oxide thickness. As a result of this the undesirable hot electron effect and the gate tunneling current is increased. In order to overcome this drawback high-k material are used instead of silicon dioxide as the insulating material underneath the gate. These modeling will prove to be beneficial and help in further research work in the future.

In this book, the channel engineering and the gate engineering techniques are combined to form novel device structures proposed as Single-halo Dual Material Gate(SHDMG) and Double-halo Dual Material gate(DHDMG) MOSFETs. Advanced MOSFETs are non-uniformly doped as a result of complex process flow. Therefore, one of the key factors to model the characteristic parameters accurately is to model its non uniform doping profile. The book also presents an analytical sub threshold surface potential, threshold voltage, drift-diffusion theory based drain current and transconductance model for linear and Gaussian profile based SHDMG and DHDMG n-MOSFETs operating up to 40nm regime. A quasi-Fermi potential based analytical sub threshold drain current model for linear as well as Gaussian profile based SHDMG and DHDMG MOS transistor, incorporating the fringing fields at the two ends of the device is also proposed.

The book gives an insight into scaling and short channel effects in MOSFETs. Also the brief idea of non conventional MOSFET structures can be obtained from the text. Beginners can go through the book to acquire knowledge on the device physics behind short channel MOSFETs.The researchers can go through the book to obtain in depth idea on developing models of novel device structures which can suppress short channel effects more effectively.

This book teaches basic and advanced concepts, new methodologies and recent developments in VLSI technology with a focus on low power design. It provides insight on how to use Tanner Spice, Cadence tools, Xilinx tools, VHDL programming and Synopsis to design simple and complex circuits using latest state-of-the art technologies. Emphasis is placed on fundamental transistor circuit-level design concepts.