Circuit-oriented IC technology simulation: Information models and integration frameworks

While advances in physical modeling of semiconductors and numerical methods has resulted in more accurate and robust Technology Computer-Aided-Design (TCAD) tools, the usability, maintainability and extensibility of these tools still remain a problem. Use of framework technology can encapsulate TCAD specific knowledge from the user, transparently transfer data between simulation modules, and improve software modularity. Although Electronic Design Automation (EDA) frameworks address software modularity issues, manipulation of data representations such as grid and strings falls purely within the domain of TCAD.;A set of utilities incorporated into an integration framework suitable for use by circuit and device designers provides encapsulation of TCAD specific knowledge from the user and seamless transfer of wafer state information between disparate simulators. The most difficult part of using device simulation is specification of the initial mesh. Initial mesh specification strongly affects simulation accuracy arid convergence properties. Parameters for a new three-level initial mesh generation scheme based on knowledge of intended device structure and operation are discussed and applied to the layout-driven analysis of latchup in a standard cell. A new transparent data interface that automatically updates process simulation grid based on updates in topography from a string-based simulator is applied to the design of a dynamic random access memory cell. Adaptive refinement within a process simulator is necessary to support interaction with generic topography simulation.;Extensibility of the current integration environment is limited by the lack of a common representation of wafer state. The Semiconductor Wafer Representation (SWR) uses an object-model along with an object-oriented interface to describe facilities which directly manipulate wafer state. Information modeling techniques are used to describe classes necessary to support numerical mesh-based simulation. A prototype of a SWR-compliant server allows analysis of the standard based on operations necessary to support the integration of current-generation simulators and the design of the next generation tools.