Computer Control and Data Management in an LSI Fabrication Facility

A minicomputer system is used to control diffusion furnaces, monitor temperatures, provide operator instructions for each processing step, and record detailed process histories for wafer lots fabricated in the Sandia Semiconductor Development Laboratory. The system provides a complete data base for laboratory operations, a variety of displays describing equipment status, scheduling and utilization summaries for equipment, wafer and mask inventories, and laboratory management information. The wafer lot history includes a record indicating the operator, time, date, and specification recipe for each process step, special notes summarizing process deviations, results of inspection steps, and in-line capacitance, oxide thickness, or resistivity measurements.