In order to meet the rapidly evolving requirements of advanced VLSI device and process design, integrated Technology CAD systems are emerging. The Viennese Integrated System for Technology CAD Applications (VISTA) is an integration and development framework which supports the implementation and use of CAD tools. The present work gives an overview of the current status of Technology CAD from a software perspective and analyzes the causes of typical TCAD problems. The application-framework architecture is presented as a key for solving many of these problems.
VISTA consists of a data level, task level, user interface, visualization, and several other generic services. The basic concepts of these parts and important implementation details are described. The scope and complexity of an application-framework for Technology CAD indicate that, besides functionality requirements, software quality deserves special attention. The quest for conceptual integrity is instrumental in creating a system which is both transparent to the user and comprehensible to the programmer.
A typical general-purpose framework service is the generation of geometry-conforming triangular grids from arbitrary grid and geometry input. The architecture and implementation of this part of VISTA is described in greater detail.
A planarized quarter micron CMOS process with shallow trench isolation serves for the demonstration of VISTA's capabilities for tool integration and simulator coupling. All system components that have been described are used in the course of the process simulation.
The re-gridding application is used to explain VISTA's integration and development support. The text concludes with a critical discussion of Technology CAD and some considerations of potential future developments.