Abstract: Disclosed are mechanisms for efficiently and accurately calculating critical area. In general terms, a method for determining a critical area for a semiconductor design layout is disclosed. The critical area is utilizable to predict yield of a semiconductor device fabricated from such layout. A semiconductor design layout having a plurality of features is first provided. The features have a plurality of polygon shapes which include nonrectangular polygon shapes. Each feature shape has at least one attribute or artifact, such as a vertex or edge. A probability of fail function is calculated based on at least a distance between two feature shape attributes or artifacts. By way of example implementations, a distance between two neighboring feature edges (or vertices) or a distance between two feature edges (or vertices) of the same feature is first determined and then used to calculate the probability of fail function.

Abstract: A complex test structure for integrated, semiconductor circuits in which the impurity regions of the test device are elongated, preferably in serpentine fashion. The elongated impurity regions emulate corresponding regions in regular integrated circuit devices. Additional regions are provided, each in elongated form, which, when impressed with appropriate voltages or currents, provide indications of defect levels and product yield in the regular devices. Advantageously, the serpentine test structure is fabricated on the same wafer and with the same process steps as the regular integrated circuit chips. In one embodiment, a plurality of such monitors are provided adjacent each other in the same test site. Regions in one monitor are selectively connected to regions in another monitor and to external contact pads by contact stations disposed between each monitor.