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.