Aspecte generale ale simul?rii proceselor tehnologice ?n microelectronic? partea IIIGeneral Aspects of Simulation Processes in Microelectronics Part 3Full text in Romanian

摘要

The paper presents the main aspects of the concept of modelling in microelectronics, as a tool used to describe the electric behaviour of devices and integrated circuits, before their manufacture, or technological processes required for manufacturing, by simulation. They highlight the main stages of technological design, in terms of simulation of a flow sheet: technological process simulation, devices simulation that make up the circuit and circuit simulation. From this point of view, there are three types of models: models of the processes that make up a flow sheet, models describing the electric behaviour of semiconductor devices and integrated circuits. There are exposed, briefly, methods of solving differential equations, with examples of analytical solution (one-dimensional Poisson equation, in the case of ideal MOS structure) and numerical solution (grid generation, discretization of differential equations), exemplifying numerical solving of Poisson equation for electrostatic potential simulation in two-dimensional structure of the MOS transistor. 1D diffusion model is considered for modelling the diffusion of low and high impurities concentration, with an example of solving one-dimensional diffusion equation by finite difference method. It also gives the Newton-Raphson iteration method for linearization of nonlinear algebraic equations, using as an example the semiconductor diode I-V characteristic.