Method and system for identifying defects in a semiconductor

A method for associating a descriptive label with an anomaly on a semiconductor wafer, the method comprising:

• placing the semiconductor wafer on a moveable stage;
• capturing and preparing one or more digital-pixel-based representations of each layer of the semiconductor wafer as each layer is manufactured;
• symbolically decomposing the digital-pixel-based representations of each layer to create a plurality of primitive-based representations of each layer;
• comparing the primitive-based representation of a last manufactured layer of the semiconductor wafer to a primitive-based reference image to detect and locate the anomaly;
• isolating primitives associated with the anomaly;
• comparing the isolated primitives associated with the anomaly with primitives in a knowledgebase to locate a set of primitives in the knowledgebase most like the isolated primitives associated with the anomaly;
• assigning a first label associated with the set of primitives in the knowledgebase that was most similar to the isolated primitives associated with the anomaly;
• and
• comparing primitives corresponding to a location of the anomaly from each of the primitive-based representations ofthe image to find a primitive-based representation ofthe image for a layer in which the anomaly first appears.

A method of identifying a defect source for a defect on a semiconductor wafer, the method comprising the steps of:

• capturing a pixel-based image of each layer of the semiconductor wafer as each layer is manufactured to form a plurality of pixel-based images;
• symbolically decomposing the plurality of pixel-based images to form a plurality of primitive-based representations of each image;
• comparing the primitive-based representation of the image for the last layer manufactured on the semiconductor device to a primitive-based reference image to detect an anomaly;
• determining an anomaly location of the anomaly;
• and
• analyzing each image in the plurality of primitive-based primitives at the anomaly location to determine on which layer an anomaly first appeared.

A system for associating a descriptive label with an anomaly on a semiconductor wafer, the system comprising:

• a moveable stage for receiving and holding the semiconductor wafer;
• a camera for capturing images of the wafer;
• a digitizer coupled to the camera for producing a digital-pixel-based representation of each layer of the semiconductor wafer as each layer is applied to produce a plurality of digital-pixel-based representations corresponding to different layers;
• a computer having a processor and memory, the computer coupled to the digitizer for receiving the plurality of digital-pixel-based representations;
• and
• the computer programmed to be operable to:
• symbolically decompose the plurality of digital-pixel-based representations to create a plurality of primitive-based representations of the image,
• compare the primitive-based representation for a last layer applied to the semiconductor wafer to a primitive-based reference image to detect and locate the anomaly,
• isolate primitives associated with the anomaly,
• compare the isolated primitives associated with the anomaly with primitives in a knowledgebase to locate a set of primitives in the knowledgebase most like the isolated primitives associated with the anomaly,
• assign a first label associated with the set of primitives in the knowledgebase that was most similar to the isolated primitives associated with the anomaly, and
• compare primitives corresponding to a location of the anomaly from each of the plurality of primitive-based representations to find a primitive-based representation of the image for a layer in which the anomaly first appears.