The investigation of a novel approach in the simulation of the trap levels effect on the conduction in a GaAs P+νN+ diode

A numerical simulation using C++ language, allowing the store of big size information (presented as (X × Y × Z) matrix) is realized, and a theoretical modelling of the charges transport in the semiconductor devices made in materials presenting a significant concentration of impurities whose energy levels are deep is implemented. The results are validated on a semi-insulating gallium arsenide (SI-GaAs) PIN structure. The numerical simulation is made by the resolution of the phenomenological transport's equations by adopting a new approach permitting to study the conduction phenomena through all the structure. From the 3D modelling, the variation of the potential profile, the free carriers and the space charge distributions, and the electrical field inside the structure are simulated. The effects of the traps are taken into account through the mechanisms of recombination and storage of a significant space charge, where the influence of the presence of these levels on the above factors is seen. Through this work a physical model intended for the study of the influence of the trap levels on the potential and the free carrier density distributions for weak lifetime semiconductors, more particularly on semi-insulating GaAs is introduced. Taking into account the trap centres is essential for a good comprehension and explanation of the transport phenomena. The present study consists to do a simulation and a modelisation of structures based on materials presenting a deep and a trap centres. A trapping model based on a combined numerical method Gummel and Newton is adopted to reduce both the run time and to reach convergence in the process when working not with one junction but with two.