The simulation of complete VLSI fabrication processes and devices
involves the cooperation of a variety of different simulation tools
to generate a model of the desired semiconductor structure, to
compute the behavior of the resulting device, and to extract
characteristic electrical parameters for further use in
circuit simulation
.
Figure 4.1 gives an overview of all simulation stages
involved in the computer-aided analysis of an integrated circuit;
feedback loops of the design process are omitted for clarity.
Figure 4.1: Simulation stages of TCAD analysis of
integrated circuits.
Each stage shown in the picture calls for running one or several simulators, with process simulation almost always requiring the complex interplay of many dissimilar programs, reflecting the fact that the fabrication process itself consists of a sequence of numerous process steps of a broad variety of types applied one after the other onto the semiconductor wafer. Interfacing these tools with one another and controlling them in a uniform way for the purpose of completely automating the entire procedure outlined in Figure 4.1 are the main concerns of this chapter.