Numerical simulation of Gate shape effect on Self-Heating in nano-MOSFET Transistors with high-k dielectric

The aim of the present work is to investigate numerically the self-heating effect (SHE) in MOSFET transistors based on high-k material taking into account the deformation of the gate under the SHE. The SHE inside the MOSFET transistor is calculated using the electrothermal model based on heat transfer equation coupled with semiconductor equations. The electrothermal model have been solved in 2D-dimension using the finite element method. The high-k dielectric HfO2 have been used as gate oxide. Several gate shapes have been used to analyze their impact on SHE. It is observed that the reduction of equivalent oxide thickness (EOT) reduces the SHE in the MOSFET transistor based in high-k dielectric material. the temperature peak increases quadratically with drain voltage for all MOSFET structures. A decrease in self-heating effect is achieved using the square gate shape.

A new hybrid method for shape optimization with application to semiconductor equations

<p style='text-indent:20px;'>The aim of this work is to reconstruct the depletion region in pn junction. Starting with famous drift diffusion model, we establish the simplified equation for the considered semiconductor. There we call the shape optimization technique to formulate a minimization problem from the inverse problem at hand. The existence of an optimal solution of the optimization problem is proved. The proposed numerical algorithm is a combined Domain Decomposition method with an efficient hybrid conjugate gradient guided by differential evolution heuristic algorithm, the finite element method is used to discretize the state equation. At the end we establish several numerical examples, to prove the validity of theoretical results using the proposed algorithm, in addition we show some simulation of the depletion region approximation under two different functioning modes.</p>

The 3D transient semiconductor equations with gradient-dependent and interfacial recombination

We establish the well-posedness of the transient van Roosbroeck system in three space dimensions under realistic assumptions on the data: non-smooth domains, discontinuous coefficient functions and mixed boundary conditions. Moreover, within this analysis, recombination terms may be concentrated on surfaces and interfaces and may not only depend on charge-carrier densities, but also on the electric field and currents. In particular, this includes Avalanche recombination. The proofs are based on recent abstract results on maximal parabolic and optimal elliptic regularity of divergence-form operators.

Numerical Study of Dual band (MW/LW) IR Detector for Performance Improvement

In the present study, an extensive numerical analysis has been performed and an effort has been made to understand the underlying physics, which is presently unclear for researchers for development of third generation FPA infrared detectors based on HgCdTe material. To reduce technology development cost associated with dualband photodetector for operation at MWIR and LWIR regions, a 2D theoretical model has been proposed including all the relevant physics. The structure under present study considers back-to-back diode structures to detect simultaneous MW/LW operative wavelength by changing the biasing polarity of the diodes. The optimum electrical and optical outputs from dualband detector have been achieved through performing design of experiments. The coupled basic semiconductor equations including nonlinear continuity, transport and Poisson’s equations have been solved to achieve electrical (I-V) characteristics under no bias condition and modern optics equations has been coupled to semiconductor equations to obtain optical characteristics. The quantum efficiency of both detectors has been computed and compared with experimental results. The computed results obtained on the basis of proposed model accurately matches with the experimental results reported by others researcher. The results exhibit the quantum efficiencies, QEMW=95 per cent and QELW=74.5 per cent, respectively.

Electro-Thermal TCAD Model for 22 kV Silicon Carbide IGBTs

This paper presents the current progress in the development of an electro-thermal numerical model for 22 kV 4H-silicon carbide IGBTs. This effort involved the creation of a TCAD model based on doping profiles and structural layers to simulate the steady-state and switching characteristics of recently-fabricated experimental devices. The technical challenge of creating this high voltage SiC IGBT model was incorporating semiconductor equations with sub-models representing carrier mobility, generation, recombination, and lattice heat flow effects with parameters conditioned for 4H-silicon carbide material. Simulations of the steady-state and switching characteristics were performed and later verified with laboratory measurements for an N-type SiC IGBT rated for 22 kV with an active area of 0.37 cm2 and a drift region of 180 μm.

A Simplified Model for SiC Power Diode Modules for Implementation in Spice Based Simulators

A simplified model for SiC Power diodes has been developed and implemented in Spice simulator in order to get the advantages of a modular and hierarchical structure that can be easily used for modeling of power semiconductor modules. The proposed approach is based on the lumped charge technique. One of the main targets for the proposed model is the implementation of a modeling structure starting from the evaluation and simplification of the semiconductor equations. The paper will show the implementation of the model along with an experimental evaluation of the proposed method.