US 6,857,114 B2 · Clustering for data compression

Abstract

An improved profileometry data collection and analysis system employing software that performs clustering analysis on library data stored in memory that represent semiconductor chip wafer profiles, for use in matching real-time data signals from data collected by profileometry instruments. To better perform a match in real-time between the incoming real-time data signals and the profile library data, cluster analysis is performed on the library data to partition the library data into clusters, and to extract representative cluster data points of the clusters. The representatives of the clusters are stored in primary memory (e.g., RAM), while the data forming the clusters are stored in secondary memory (e.g., a hard drive). A real-time data signal is then first compared to the representative cluster data points, and when a match is made with a particular representative cluster data point, the cluster associated with the representative cluster data point is loaded from secondary memory into primary memory. Next a further search is made with the incoming real-time data signal to find the closest match to the data in the cluster. In this way the entire library data does not have to be searched sequentially, and the entire library does not have to reside in primary memory in order to be quickly searched, which both conserves time and primary memory. Techniques are disclosed to further refine special cases of points residing on the boundary of the cluster. In a preferred embodiment, the partitioning method for the cluster is based on the T. Gonzalez algorithm.

Claims24

Dependent claims

A method of ascertaining a physical property of an integrated circuit (IC) device, the method comprising:

collecting a data signal from a profileometry instrument;
comparing the collected data signal to a set of representative data points to determine a closest matching representative data point,
wherein each representative data point in the set of representative data points corresponds to a cluster of data points, and
wherein each data point in the cluster of data points corresponds to a physical property of the IC device;
comparing the collected data signal to the cluster of data points corresponding to the closest matching representative data point to determine a closest matching data point;
and
determining the physical property of the IC device based on the data point corresponding to the closest matching data point.

4 more elements

Dependencies are inferred from the claim text.

Clustering for data compression

Life of this patent

Clustering for data compression

Life of this patent

Abstract

Claims24