Methods and apparatus for data analysis
A method and apparatus for data analysis according to various aspects of the present invention is configured to test a set of components and generate test data for the components. A diagnostic system automatically analyzes the test data to identify a characteristic of a component fabrication process by recognizing a pattern in the test data and classifying the pattern using a neural network.
1. A test data analysis system for analyzing test data generated by an automatic test equipment for a set of semiconductor components fabricated using a fabrication process and identifying a problem in the fabrication process, the system comprising:
a processor configured to obtain the test data for the set of semiconductor components and to implement a diagnostic system; and
a memory configured to store the test data;
wherein the diagnostic system:
filters the test data using a neural network configured to filter the test data, wherein the neural network comprises a self-organizing map;
recognizes a pattern in the filtered test data corresponding to a recognized spatial pattern of the set of semiconductor components when the filtered test data is superimposed onto a wafermap;
compares the recognized spatial pattern to a known spatial pattern associated with the problem;
retrieves a stored neural network from the neural network library to analyze the filtered test data;
classifies, using the stored neural network, the recognized spatial pattern according to the known spatial pattern, wherein the stored neural network comprises a self-organizing map and at least two stages, wherein:
a first stage comprises a plurality of classifiers configured to receive different types of test data and generates first stage data based on the different types of test data; and
a second stage configured to receive the first stage data from the plurality of classifiers and classify the known spatial pattern using the neural network based on the first stage data;
identifies the problem in the fabrication process based on a classification of the recognized spatial pattern; and
produces a report comprising the problem in the fabrication process.
2. A test data analysis system according to claim 1 , wherein the first and second stages comprise self-learning systems, and the first and second stages are independently trainable.
3. A test data analysis system according to claim 1 , wherein the diagnostic system comprises a classifier configured to classify the recognized spatial pattern according to the known spatial pattern.
4. A test data analysis system according to claim 3 , wherein the diagnostic system comprises a feature extractor configured to extract a feature from the test data associated with the recognized spatial pattern.
5. A test data analysis system according to claim 4 , wherein the feature extractor is configured to extract at least two features from the test data, and wherein the diagnostic system further comprises a feature selector configured to select fewer than all of the features for analysis.