Scanning electron microscope system and method of manufacturing an integrated circuit
AssigneeAgere Systems Inc.
InventorsBrittin Charles Kane, John Martin McIntosh
Life of this patent
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Abstract
A method and system for analyzing a substrate including the step of scanning the substrate to produce an intensity signal which represents the topography of the wafer to a first order. Other contributions to the signal intensity may be chemical composition and electrical state of the scanned features on the substrate. The scanned signal is compared and correlated to a reference signal to assess the substrate. The present invention is also directed to a method of manufacturing a wafer using the method and system and improving the manufacturing quality of product.
Claims15
A method for analyzing a substrate having a raised surface feature, the method comprising the steps of:
- (a) scanning the substrate to produce an intensity signal;
- (b) processing the intensity signal using an auto-correlation operation to produce a processed signal and converting the processed signal to the frequency domain, wherein the auto-correlation operation produces a wafer auto-correlation signal from a filtered waveform signal;
- (c) providing a reference signal;
- and
- (d) comparing the processed signal to the reference signal.
A method of manufacturing an integrated circuit comprising the steps of:
- (a) providing a wafer with at least one surface feature;
- (b) scanning the wafer to produce an intensity signal representing the surface feature;
- (c) processing the intensity signal using an auto-correlation operation to produce a processed signal and converting the processed signal to the frequency domain, wherein the auto-correlation operation produces a wafer auto-correlation signal from a filtered waveform signal;
- (d) providing a reference signal;
- and
- (e) comparing the scanned signal to a reference signal.
A substrate analyzing system for analyzing a substrate having a surface feature, the substrate analyzing system comprising:
- a scanning electron microscope for producing an intensity signal of the substrate;
- auto-correlation means for implementing an auto-correlation operation to produce an auto-correlation signal from the intensity signal, wherein the auto-correlation operation produces a wafer auto-correlation signal from a filtered waveform signal;
- converter means for converting the auto-correlation signal into the frequency domain;
- cross-correlation means for generating a cross-correlation signal of the auto-correlation signal and a reference signal to produce a cross-correlation signal;
- and
- means for evaluating the substrate in response to the cross-correlation signal.
Dependencies are inferred from the claim text.