Technology CAD, TCAD, is a term that describes a collection of model-based tools and methodologies that are used to assist process technology development, IC manufacturing control and the coupling of process specific behavior to products design. Different levels of model complexity, physics content and accuracy are needed depending on the development stage of a particular technology. The continuos need to understand and solve ever more difficult problems rapidly without escalating costs has forced us to draw and integrate results from multiple disciplines, enabling us to keep up with the relentless pace of silicon technology evolution. This presentation will review the scope of these tools, the infrastructure required for their rapid development and deployment and the benefits that result from their application to the exploration, development and manufacturing of new process technologies.