Spectral Element Method Analysis Of Transient Electrothermal Characteristics Of Deep Submicron Semiconductor Devices

Semiconductor devices is a basic element of modern electronic equipment.As the Moore Law predicts,the innovation of the integrated circuits goes really fast with the higher degree of integration,and the rapid development of new material and new technology.On the one hand,it greatly improves the capability of electronic devices to meet the people's rapidly changing demands for the technology progressing.On the other hand,the miniaturization of integrated circuit technology also promotes the constant progress of the semiconductor technology research and manufacturing technology.During the innovation process,the computational simulation enables us to get the operational parameter of the semiconductor device needing no real devices.Thus,it plays an very important role in semiconductor development.The traditional way of semiconductor simulation usually uses the drift-diffusion equations to calculate the electron concentration,hole density and electric potential.However,when the size of the semiconductor device miniaturize to submicron or even deep submicron,the drift-diffusion equations are not able to describe the physical phenomenon inside the device,such as the velocity overshoot.In such case,we can not get an accurate result of the semiconductor simulation.In order to solve this problem,we introduce the hydrodynamic model in this thesis.This thesis aims to analyze and simulate the transient electro-thermal process of PIN and metal-oxide semiconductor field-effect transistor(MOSFET)by spectral-element time-domail method.The main contribution is shown as follows:Firstly,taking PIN as an example,we can obtain the electrical characteristics of PIN under transient impulse by deriving the spectral-element time-domain formula and the self-consistent model.By solving the heat conduction equation,the transient thermal characteristics of PIN are also obtained.Then,considering the effect of temperature on the items such as the mobility,electron,and hole-density energy balance equation,a coupled model of transient electro-thermal characteristics of PIN is achieved.Secondly,MOSFET is used for analyzing the hydrodynamic equation based on spectral-element time-domain derived.Then,we can get the electron concentration,hole density,electron temperature,hole temperature,potential distribution inside the semiconductor under different voltages.Moreover,considering the heat radiation of the semiconductor,we add a copper heat sink to the bottom to start a co-simulation process in order to observe the heat distribution of the model.This is solved for the integrated simulation of the MOSFET.Finally,a GaAs-based MESFET is described hydrodynamic model equation under the Schottky boundary condition is provided,and the principle of MESFET was analyzed.The transient electxo-thermal characteristics of GaAs MESFET under transient signal are achieved.