Process excursion detection
A method for analyzing defect information on a substrate, including logically dividing the substrate into zones, and detecting defects on the substrate to produce the defect information. The defect information from the substrate is analyzed on a zone by zone basis to produce defect level classifications for the defects within each zone. The zonal defect level classifications are analyzed according to at least one analysis method. The defect level classifications are preferably selected from a group of defect level classifications that is specified by a recipe. Preferably, the at least one analysis method includes at least one of zonal defect distribution, automatic defect classification, spatial signature analysis, and excursion detection. The defect level classifications preferably include at least one of individual defect, defect cluster, and spatial signature analysis signature. In one embodiment the defect information is logically divided into configurable zones after the defects on the substrate have been detected.
1. A method for detecting process excursions from defect information from a substrate, the method comprising the steps of:
analyzing the defect information based on a list of selectable factors to determine spatial signature analysis signatures, and
selectively assigning a process problem identification to the substrate based on a combination of more than one spatial signature analysis signatures detected on the substrate,
wherein the step of selectively assigning the process problem identification is accomplished with a table that includes a numeric process problem identification, a string process problem identification, a Boolean expression of component spatial signature analysis signatures, a remedial action, a notification action, a layer identification, and a severity level.
2. The method of claim 1 , wherein the list of selectable factors includes at least one of a number of events, an average density of an event, a number of die affected, an effective length of event, an area covered by event, and a location of event relative to substrate center.
3. The method of claim 1 , wherein the step of selectively assigning a process problem identification to the substrate further comprises assigning a substrate identification to the substrate and storing the substrate identification and the process problem identification in a database.
4. The method of claim 1 , wherein more than one process problem identification can be assigned to each substrate.