Remote fabrication of integrated circuits : software support for the M.I.T. computer aided fabrication environment

The Computer Aided Fabrication Environment (CAFE) is a software system developed at MIT for use in all phases of integrated circuit fabrication. While still undergoing development and enhancements, CAFE provides day-to-day support to research and production facilities at MIT, with both standard and flexible product lines. One of the limitations of the present CAFE system is that it is not a fully open system. An open system is one that is designed to accommodate components from various software applications and can be viewed from three perspectives: portability, integration, and interoperability. This document is concerned with the idea of interoperability between different Computer Integrated Manufacturing (CIM) systems, and describes the extension to CAFE's architecture to support what is called Remote Fabrication. With the goal of general interoperability between different CIM systems in mind, the Virtual Object Manager is developed. The Virtual Object Manager provides a framework for three key modules to support interoperability: the Object Management Module, the Export/Import Module, and the Remote Message Passing Module. Each of these modules are discussed and implemented for the CAFE platform. Building upon the interoperability tools in the Virtual Object Manger, application layer support is then developed for the specific task of remote fabrication in CAFE. The application modules and additional software tools are described, and together form the CAFE Remote Fabrication System, a prototype system providing remote fabrication capabilities. An example of a remote fabrication session is described, stepping the reader through CAFE's remote processing paradigm and showing how the various tools are used. In the form of a tutorial, the example starts with installing a process flow into the CAFE database and creating a lot of wafers. The operate-machine/next-operation processing cycle is then done using both local and remote machines, showing the interoperability features at work. When the processing cycle completes a traveller file is generated, summarizing the entire history of processing. While this document describes and implements a remote fabrication system specifically for CAFE, it is hoped that this document brings into focus some of the issues involved in general interoperability between different CIM systems, and provides a useful framework for future work. Thesis Supervisor: Donald E. Troxel Professor of Electrical Engineering Title: Acknowledgments I would like to thank Greg Fischer for his help in answering many of my questions regarding the CAFE system. He has endured my questioning on all aspects of CAFE, including describing the various application modules, their purpose, and their gory details; helping me understand the uses of the objects in the CAFE database; and providing general Lisp language help, pointers, and tips. His feedback was friendly, quick, practical, and extremely valuable. Tom Lohman provided extensive help in dealing with and understanding the Ingres database. Without his help, some of the key objects and ideas described in this document would never have surfaced. I'd like to thank Mike McIlrath for being the Lisp and GESTALT interface guru. He has been very constructive in helping me learn the details of Lisp and CLOS, the Common Lisp Object System. His wisdom, experience, and sense of humor have stimulated many interesting theories which led the way to many of the ideas presented in this document. John Carney's work on message passing, in particular his socket routines, was crucial to the overall development of CAFE's interoperability tools. He also provided many helpful tips on the remote fabrication project during my numerous conversations with him. I'd like to thank William Moyne, James Kao, Myron Freeman, and Francis Doughty for providing a pleasant and friendly environment to work in. Finally, I'd like to thank Professor Troxel for making all this work possible. This work has been made possible by support from the Advanced Research Projects Agency (ARPA) under Contract N00174-93-C-0035.