This work describes the Semiconductor Wafer Representation (SWR) for representing and manipulating wafer state during process and device simulation. The goal of the SWR is to provide an object-oriented interface to a collection of functions designed for developing and integrating Technology CAD (TCAD) applications. By providing functions which can be common across many applications, we aim to greatly reduce tool development and integration time. Corporate, vendor, and university TCAD developers have worked together under the auspices of the CAD Framework Initiative to create an architecture and C++ programming interface for an SWR 1.0 draft standard. Here we describe this architecture and the results of creating and using a prototype implementation of the standard both to integrate existing TCAD tools and to develop simple new tools.>

A workstation-based integrated system with a highly interactive X/Motif user interface is discussed. At present, TSUPREM3, TSUPREM4 and TPISCES have been integrated into this system. The components of the integrated TCAD system include a generic process recipe editor, a mask editor, a 2-D wafer structure builder (using 1-D/2-D process simulation profiles), a mesh generator for 2-D device simulation, a device simulation recipe editor, and graphical postprocessors for both process and device analysis. The user of this system inputs the specification of a process recipe and the layout of the device structure to be fabricated. The system then runs process and device simulation using incremental and shared simulation strategies to generate wafer structure and electrical device characteristics. An interactive user interface guides the user through the process and device simulation flow. thereby aiding what-if analysis of process and device tradeoffs.>

Random fluctuations in very large scale integrated circuit (VLSIC) fabrication processes cause the parametric production yield to fall below acceptable levels, resulting in a loss of competitive edge. To address this problem, a framework for an integrated computer-aided-design-computer-aided-manufacturing (CAD-CAM) system that will enable the design, fabrication, control, and diagnosis of present and future VLSICs to be carried out profitably is proposed. It is argued that the inefficiencies of present-day CAM systems are due to the lack of appropriate methodologies for process monitoring and statistical techniques to analyze the in-process and end-of-process data. Methodologies for monitoring lots in fabrication lines, using in situ measurements, and for controlling lots, using the multivariate distribution of observable in-process parameters, are discussed. These methodologies attempt to eliminate the pitfalls of the previous statistical process control algorithms. The software system that implements the algorithms has shown encouraging results when applied to industrial fabrication lines.