No abstract

Yield loss can be characterized as either catastrophic or parametric. Catastrophic yield loss is primarily due to local disturbances, such as spot defects, that occur in a manufacturing process. On the other hand, parametric yield loss is due to global disturbances, such as mask misalignment. In this paper we briefly explore these two different types of yield loss and then review some methods that have been developed to maximize parametric yield.

No abstract

Today's complex design processes feature large numbers of varied, interdependent constraints, which often cross interdisciplinary boundaries. Therefore, a computersupported constraint management methodology that automatically detects violations early in the design process, provides useful violation notification to guide redesign efforts, and can be integrated with conventional CAD software can be a great aid to the designer. We present such a methodology and describe its implementation in the Minerva II design process manager, along with an example design session.1 Although not focused in electronic design, work in the area of concurrent engineering [7,9] has produced tools that help designers detect and resolve violations of some types of parametric constraints. These tools cannot generate and evaluate constraints of arbitrary form.DAC 99, New Orleans, Louisiana: (c) 1999 ACM 1-58113-109-7/99/06..$5.00 Fig. 9. Constraint and property browser. In the graph, property nodes are dark, constraint nodes are light-shaded, and selected nodes are white. The user is currently examining the information generated by the constraint manager about the "Yield" property and the "resolution requirement" constraint.

Task management involves task creation and execution. These are facilitated using a task schema as exemplified in the Hercules Task Manager. Experience with Hercules has shown the task schema to be very useful for task creation, but less than ideal for task resolution, i.e., the selection of tool and data resources to be used in execution. Tool/data interactions often lead to resource selection constraints that cannot be captured using dependency relationships in the schema. We have addressed this by adding conditions to the task schema which use task-level meta-data to constrain resource selection. With examples we show that conditions are useful for handling a wide variety of real constraints.